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Journal of Oleo Science Copyright 2015 by Japan Oil Chemists' Society doi : 10.5650/jos.ess15120 J. Oleo Sci. 64, (11) 1213-1226 (2015)
Preparation of Optically Active δ-Tri- and
δ-Tetradecalactones by a Combination of Novozym
435-catalyzed Enantioselective Methanolysis and Amidation
Yasutaka Shimotori1, Masayuki Hoshi1, Hayato Okabe2 and Tetsuo Miyakoshi2
1 Department of Biotechnology and Environmental Chemistry, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507, JAPAN
2 Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki 214-8571, JAPAN

Abstract: A combination of Novozym 435-catalyzed methanolysis and amidation using racemic N-methyl-
5-acetoxytridecan- and tetradecanamides as a substrate proceeded in good enantioselectivity to afford the
cyclohexyl-5-hydroxyalkanamides. Both enantiomers of δ-tri- and δ-tetradecalactones were synthesized in
over 90% enantiomeric excesses from the corresponding (R)- or (S)-alkanamides. Addition of
cyclohexylamine to Novozym 435-catalyzed methanolysis shortened 24-hour reaction time to reach about
50% conversion. Enantiomers of optically active δ-tri- and δ-tetradecalactones had different odors and
Key words: δ-tridecalactone, δ-tetradecalactone, lipase-catalyzed kinetic resolution, methanolysis, amidation
and anti-invasive activities33 . Different biological activities, Lactones are well-known flavor component in many such as anti-bronchoconstrictor, enzyme inhibitory, and natural products15 , sex pheromone components69 and anti-inflammatory activity, are generally exhibited by each useful building blocks for various drugs1012 . These lac- enantiomer in many cases3439 . Therefore, the anti-tumor tones play important roles in the food and fragrance indus- and anti-invasive effects of optically active enantiomers tries because they add sweet, milky, and fruity notes to could be expected to be different than those of racemates. many products1315 . However, the odor quality and thresh- We previously reported a method for the synthesis of opti- old depend to a large extent on the chiral configuration cally active δ-hexadecalactone by a combination of lipase- and enantiomeric composition13, 1618 . Lactones are found catalyzed enantiomeric methanolysis and amidation40 . It naturally enantiomeric excess in various compositions19 21 . was clear that the addition of two equivalent amounts of Therefore, use of similar enantiomeric excesses of optically cyclohexylamine to the substrate increased enantiolselec- active lactones is prerequisite to artificially simulate a tivity over 10 relative to the absence of the amine. In this natural flavor. δ-Tri- and δ-tetradecalactones are found in study, we attempted to synthesize optically active δ-tri- milk and dairy products such as cheddar, Gouda and blue and δ-tetradecalactones using this method.
cheese2227 . The enantiomeric excess composition of δ-tetradecalactone contained in these dairy products is generally R -enantiomer dominant28 . Additionally, δ-tetradecalactone is widely found in cooked beef, sheep and chicken fats2931 . Sensory evaluation of racemic δ-tetradecalactone was performed by Schlutt et al.32 , dif- All reagents and solvents were obtained from commer- ferences in odor properties and thresholds among enantio- cial sources. 1H NMR spectra were recorded in CDCl3 using mers of δ-tri- and δ-tetradecalactones have not been re- a JNM-ECA-400 spectrometer 400 MHz; JEOL, Tokyo, ported. We synthesized these optically active lactones and Japan . Chemical shifts are expressed in parts/million evaluated their sensory properties. Tanaka et al. reported , with tetramethylsilane as the internal standard. 13C that racemic δ-tri- and δ-tetradecalactones have anti-tumor NMR spectra were recorded in CDCl3 using a JNM-ECA- Correspondence to: Yasutaka Shimotori, Department of Biotechnology and Environmental Chemistry, Kitami Institute of Technology,
165 Koen-cho, Kitami, Hokkaido 090-8507, JAPAN
E-mail: [email protected]
Accepted July 31, 2015 (received for review May 19, 2015)
Journal of Oleo Science ISSN 1345-8957 print / ISSN 1347-3352 online Y. Shimotori, M. Hoshi and H. Okabe et al. 400 spectrometer 100 MHz, JEOL . Chemical shifts are 25.2, 26.1, 29.0, 29.2, 29.3 -CH2- 5 , 31.7 CH3NHC expressed in parts/millionppm , with tetramethylsilane as 33.4, 33.9 -CH2CH OAc CH2- , 35.8 -NHC the internal standard. Stractural determination of all com- 73.7 -CH2CH OAc CH2- , 171.0 -OC pounds was performed by the use of COSY, HMQC, and O - . HRMS FD calcd. for C16H32NO3 MH HMBC NMR techniques. Optical rotations were measured 286.2382; foundMH , 286.23314.
with a P-1010 JASCO Corp., Tokyo, Japan . IR spectra were measured with an IR-4100 JASCO Corp. Melting Yield: 2.73 g, 87 from rac-5 ; colorless solid; mp points were recorded on a MP-500D Yanaco Technical 35-36 ; α 25D0.89 c0.5, MeOH, 34 e.e. for R Science Co., Ltd., Kyoto, Japan and are uncorrected. En- -1b . IR KBr : cm 1 3306 N-H , 2919 -CH3 , 2850 -CH2- , antiomeric excesses were determined by capillary GC using , 1241 C-O . 1H NMR 400 an InertCap CHIRAMIX 30 m0.25 mm I.D. 0.25 μm film MHz, TMS/CDCl3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 0.92 thickness, GL Science Co., Ltd., Tokyo, Japan columnInj. t, J7.5 Hz, 3H, CH 3CH2CH2NH CO - , 1.25 m, 11H, . High-resolution mass spectra were an- , 1.52 m, 4H, -CH2CH OAc CH2- , 1.57 m, 2H, alyzed on an AccuTof GCv 4G JEOL .
- , 1.62 m, 1H, -NHCO O CH2CH2- , 2.04 s, 3H, -OC 2.2 Preparation of racemic N-alkyl-5-acetoxyalkanamides CH3 , 2.17 m, 2H, -NHC O CH2- , 3.20 dt, J6.3, 6.9 rac-1 and rac-2 40 Hz, 2H, CH3CH2CH2NHC O - , 4.87 tt, J5.7, 5.7 Hz, Racemic δ-tridecalactone 10.0 mmol, 2.12 g or CH2- , 5.78br s, 1H, NH δ-tetradecalactone10.0 mmol, 2.26 g was added to a solu- MHz, TMS/CDCl3 : δ 11.3 CH3CH2CH2NHC tion of methylamine hydrochloride 15.0 mmol, 1.0 g and -CH2CH3 , 21.2 -NHC O CH2CH2- , 21.5 -CH2- , 22.5 potassium acetate 15.0 mmol, 1.47 g in THF 50 mL and O - , 22.8, 25.2, 29.1, 29.4, 31.7 stirred at room temperature. Alternatively, a crude mixture , 33.5, 34.0-CH 2CHOAc containing lactone 10.0 mmol and the corresponding O CH2- , 41.1 CH3CH2CH2NHC O - , 73.6 -CH2CH amine 20.0 mmol was stirred at room temperature. The OAc CH2- , 171.0 -OC O CH3 , 172.5 -NHC mixture was evaporated, the residue was dissolved in HRMS FD calcd. for C18H36NO3 MH , 314.2695; found CHCl3 and water was then added. The aqueous layer was , 314.27011.
separated, and the organic layer was washed with water, dried over anhydrous MgSO4, filtered, and concentrated. Yield: 2.69 g, 86 from rac-5 ; colorless solid; mp Purification of the crude product by recrystallization from 35-36 ; α 25D5.74 c0.5, MeOH, 70 e.e. for R n-hexane gave the corresponding N-alkyl-5-hydroxyal- -1c . IR KBr : cm 1 3306 N-H , 2920 -CH3 , 2850 -CH2- , kanamides rac-1 and 2 . Acetic anhydride 16.0 mmol, , 1242 C-O . 1H NMR 400 1.63 g and 4-dimethylaminopyridine 1.60 mmol, 0.20 g MHz, TMS/CDCl3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 1.13 were added to a stirred solution of rac-1 or 2 in anhydrous d, J2.9 Hz, 3H, O - , 1.15 d, J2.3 CH2Cl2 20 mL at room temperature. After 24 hours, CH2Cl2 Hz, 3H, CH3 2CHNHC O - , 1.26 m, 12H, -CH2-6 was removed under reduced pressure. Water 50 mL was 1.56 m, 4H, -CH2CH OAc CH2- , 1.60 m, 1H, -NHC then added, and the solution was neutralized with NaCO3. CH2CH2- , 1.68 m, 1H, -NHC O CH2CH2- , 2.04 s, 3H, CH3Cl was added to the mixture and the organic layer was O CH3 , 2.13 m, 2H, -NHC O CH2- , 4.07 dq, J separated, washed with water, dried over MgSO4, filtered, 6.3, 6.9 Hz, 1H, O - , 4.86 tt, J6.3, and concentrated. Purification of the crude product by 5.7 Hz, 1H, -CH2CH OAc CH2- , 5.45 br s, 1H, NH . 13C silica gel column chromatographyn-hexane/EtOAc, 1:1, v/ NMR100 MHz, TMS/CDCl 3 : δ 14.2-CH 2CH3 , 21.3-NHC v gave the desired compounds rac-1a-e and 2a-e.
O CH2CH2- , 21.6-CH 2- , 22.7, 22.8 CH3 2CHNHC O - , 25.4, 29.3, 29.5, 31.9 -CH2-4 , 33.5, 34.1 -CH2CH Yield: 2.62 g, 92 from rac-5 ; colorless solid; mp OAc CH2- , 36.4 -NHC O CH2- , 41.3 CH3 2CHNHC 35-36 ; α 25D6.34 c0.5, MeOH, 77 e.e. for R - O - , 73.8 -CH2CH OAc CH2- , 171.1 -OC 1a . IR NaCl : cm 1 3300 N-H , 2952 -CH3 , 2925 -CH2- , O - . HRMS FD calcd. for C18H36NO3 M 2872 -CH3 , 2857 -CH2- , 1738 OCO H , 314.2695; foundMH , 314.26682.
1242 C-O . 1H NMR 400 MHz, TMS/CDCl3 : δ 0.88 t, J 7.2 Hz, 3H, -CH2CH3 , 1.25m, 12H, -CH 2-6 Yield: 3.32 g, 94 from rac-5 ; colorless solid; mp -CH2CH OAc CH2- , 1.65 m, 2H, -NHC 40-41 ; α 25D1.64 c0.5, MeOH, 32 e.e. for R CH3 , 2.16m, 2H, -NHC O -1d . IR KBr : cm 1 3303 N-H , 2920 -CH3 , 2852 -CH2- , 2.80 d, J4.4 Hz, 3H, CH 3NHC , 1246 C-O . 1H NMR 400 -CH2CH OAc CH2- , 5.59 br s, 1H, NH . 13C NMR 100 MHz, TMS/CDCl3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 1.13 MHz, TMS/CDCl3 : δ 13.9 -CH2CH3 , 21.1 -OC m, 3H, -CH 2CHCH 2- NHCO - , 1.26m, 12H, -CH 2- O CH2CH2- , 22.5 -CH2CH OAc CH2CH2- , 6 , 1.37 m, 2H, -CH2- at cHx , 1.56 m, 6H, -CH2CH Ac J. Oleo Sci. 64, (11) 1213-1226 (2015)
Preparation of optically active δ-tri- and δ-tetradecalactones CH2-, -CH2CH2CH CH2- NHC O - , 1.69 m, 3H, -NHC O CH2CH2-, -CH2CH2CH CH2- NHC Yield: 2.95 g, 90 from rac-6 ; colorless solid; mp 2H, -CH2CH2CHCH 2- NHCO - , 2.04s, 3H, -OC O 35-36 ; α 25D0.24 c0.5, MeOH, 78 e.e. for R CH3 , 2.14 m, 2H, -NHC O CH2- , 3.76 m, 1H, -CH2CH -2b . IR KBr : cm 1 3304 N-H , 2917 -CH3 , 2850 -CH2- , O - , 4.87 tt, J6.3, 5.7 Hz, 1H, -CH 2CH , 1242 C-O . 1H NMR 400 CH2- , 5.43br s, 1H, NH . 13C NMR100 MHz, TMS/ MHz, TMS/CDCl3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 0.92 CDCl3 : δ 14.2-CH 2CH3 , 21.3-OC O t, J7.5 Hz, 3H, CH 3CH2CH2NHC CH2CH2- , 22.7-CH 2- , 24.9-CH 2CH2CHCH 2- NHC , 1.55 m, 7H, CH3CH2CH2NHC - , 25.4-CH 2- at cHx , 25.6, 29.3, 29.6, 31.9-CH 2- CH2- , 1.69m, 1H, -NHC O CH2CH2- , 2.04s, 4 , 33.3 -CH2CH CH2- NHC O - , 33.5, 34.1 -CH2CH O CH3 , 2.17 m, 2H, -NHC OAc CH2- , 36.5 -NHC O CH2- , 48.2 -CH2CH CH2- dt, J5.7, 5.7 Hz, 2H, CH 3CH2CH2NHCO - , 4.87tt, J O - , 73.8 -CH2CH OAc CH2- , 171.2 -OC 5.7, 5.7 Hz, 1H, -CH 2CHOAc CH2- , 5.66br s, 1H, NH calcd. for C21H40NO3 C NMR 100 MHz, TMS/CDCl3 : δ 11.4 CH3CH2CH2NHC , 354.3008; foundMH , 354.29927.
O - , 14.2 -CH2CH3 , 21.4 -NHC O CH2CH2- , 21.6, -CH2- , 22.7 CH3CH2CH2NHC O - , 23.0, 25.4, 29.4, Yield: 3.47 g, 96 from rac-5 ; colorless solid; mp 29.6, 29.6, 32.0-CH 2-6 , 33.6, 34.1-CH 2CHOAc 40-41 ; α 25D2.62 c0.5, MeOH, 47 e.e. for R O CH2- , 41.2 CH3CH2CH2NHC -1e . IR KBr : cm1 3301 N-H , 3030 Ar, C-H , 2919 73.8 -CH2CH OAc CH2- , 171.2 -OC -CH3 , 2852 -CH2- , 1723 OCO O - . HRMS FD calcd. for C19H38NO3 MH 1544, 1455 Ar, CC , 1242 C-O , 746, 699 Ar, C-H . 1H 328.2852; foundMH , 328.28214.
NMR 400 MHz, TMS/CDCl3 : δ 0.88 t, J6.9 Hz, 3H, -CH2CH3 , 1.25 m, 12H, -CH2-6 , 1.51 m, 2H, -CH2CH Yield: 2.88 g, 88 from rac-6 ; colorless solid; mp OAc CH2- , 1.57 m, 2H, -CH2CH OAc CH2- , 1.63 m, 1H, 38-39 ; α 25D4.18 c0.5, MeOH, 50 e.e. for R O CH2CH2- , 1.71 m, 1H, -NHC -2c . IR KBr : cm 1 3305 N-H , 2918 -CH3 , 2848 -CH2- , CH3 , 2.21m, 2H, -NHC O , 1242 C-O . 1H NMR 400 4.42d, J6.0 Hz, 2H, PhCH 2NHCO - , 4.86tt, J6.9, MHz, TMS/CDCl3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 1.13 5.7 Hz, 1H, -CH2CH OAc CH2- , 5.92 br s, 1H, NH , 7.27 d, J2.3 Hz, 3H, O - , 1.15 d, J2.9 m, 3H, Ph , 7.32 m, 2H, Ph . 13C NMR 100 MHz, TMS/ Hz, 3H, CH3 2CHNHC O - , 1.25 m, 14H, -CH2-7 CDCl3 : δ 14.0-CH 2CH3 , 21.2-OC O 1.55 m, 4H, -CH2CH OAc CH2- , 1.60 m, 1H, -NHC O CH2CH2- , 22.6, 25.3, 29.2, 29.4, 31.8 -CH2-5 CH2CH2- , 1.68 m, 1H, -NHC O CH2CH2- , 2.04 s, 3H, 33.5, 34.0 -CH2CH OAc CH2- , 36.1 -NHC O CH3 , 2.13 m, 2H, -NHC O CH2- , 4.07 dq, J - , 73.6-CH 2CHOAc 6.3, 6.9 Hz, 1H, O - , 4.86 tt, J5.7, 127.8, 128.6, 138.3 Ph4 5.7 Hz, 1H, -CH2CH OAc CH2- , 5.37 br s, 1H, NH . 13C O - . HRMS FD calcd. for C22H35NO3 M , NMR100 MHz, TMS/CDCl 3 : δ 14.2-CH 2CH3 , 21.4-NHC , 361.25891.
CH2CH2- , 21.6-CH 2- , 22.7, 22.8 CH3 2CHNHC O - , 22.9, 25.4, 29.4, 29.6, 29.6, 32.0 -CH2-6 Yield: 2.81 g, 94 from rac-6 ; colorless solid; mp 34.1 -CH2CH OAc CH2- , 36.4 -NHC 47-48 ; α 25D0.18 c0.5, MeOH, 84 e.e. for R O - , 73.8 -CH2CH OAc CH2- , 171.1 -2a . IR KBr : cm1 3271, 3091 N-H , 2952 -CH3 , 2925 O CH3 , 171.8 -NHC O - . HRMS FD calcd. -CH2- , 2872 -CH3 , 2857 -CH2- , 1738 OC O , 1652 , 328.2852; found MH . 1H NMR400 MHz, TMS/CDCl 3 : δ 0.88 t, J7.2 Hz, 3H, -CH 2CH3 , 1.22 m, 14H, -CH2-7 1.52 m, 4H, -CH2CH OAc CH2- , 1.65 m, 2H, -NHC Yield: 3.38 g, 92 from rac-6 ; colorless solid; mp CH2CH2- , 2.04 s, 3H, -OC O CH3 , 2.17 m, 2H, -NHC 40-41 ; α 25D1.42 c0.5, MeOH, 74 e.e. for R CH2- , 2.80d, J4.8 Hz, 3H, CH 3NHCO -2d . IR KBr : cm 1 3301 N-H , 2920 -CH3 , 2851 -CH2- , m, 1H, -CH 2CHOAc CH2- , 5.54br s, 1H, NH , 1245 C-O . 1H NMR 400 100 MHz, TMS/CDCl3 : δ 14.1 -CH2CH3 , 21.2 -OC MHz, TMS/CDCl3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 1.12 O CH2CH2- , 22.6 -CH2CH OAc m, 3H, -CH 2CHCH 2- NHCO - , 1.25m, 14H, -CH 2- CH2CH2- , 25.3, 26.2, 29.3, 29.4, 29.5, 29.6-CH 2-6 7 , 1.36m, 2H, -CH 2- at cHx , 1.56m, 6H, -CH 2CHOAc O - , 33.6, 34.0 -CH2CH OAc CH2- , 36.1 CH2-, -CH2CH2CH CH2- NHC O - , 1.70 m, 3H, -NHC O CH2- , 73.7 -CH2CH OAc CH2- , 171.0 -OC O CH2CH2-, -CH2CH2CH CH2- NHC O CH3 , 173.2 -NHC O - . HRMS FD calcd. for 2H, -CH2CH2CHCH 2- NHCO - , 2.04s, 3H, -OC O , 300.2539; foundMH , 300.25039.
CH3 , 2.13 m, 2H, -NHC O CH2- , 3.76 m, 1H, -CH2CH O - , 4.87 tt, J6.3, 5.7 Hz, 1H, -CH 2CH J. Oleo Sci. 64, (11) 1213-1226 (2015)
Y. Shimotori, M. Hoshi and H. Okabe et al. CH2- , 5.43br s, 1H, NH . 13C NMR100 MHz, TMS/ 5-acetoxytridcanamide R -1a 0.13 g, 46 , S -N- CDCl3 : δ 14.2-CH 2CH3 , 21.4-OC O methyl-5-hydroxytridecanamide S -3a 0.05 g, 21 CH2CH2- , 22.7-CH 2- , 24.9-CH 2CH2CHCH 2- NHC and S -δ-tridecalactone S -5 0.06 g, 27 O - , 25.4 -CH2- at cHx , 25.6, 29.4, 29.6, 29.6, 32.0 tonization of R -1a and S -3a is described in reference , 33.3 -CH2CH CH2- NHC 4141 . R -1a and S -3a were hydrolyzed 10 NaOH in -CH2CH OAc CH2- , 36.5 -NHC at 90 for 3 h, and then cooled. A 10 O - , 73.8 -CH2CH OAc CH2- , H2SO4 methanol solution was added dropwise to the O CH3 , 171.6 -NHC mixture at 0 to pH 3. After evaporation, water 50 mL calcd. for C22H42NO3 MH , 368.3165; found MH were added, and the organic layer was separated. The aqueous phase was extracted with EtOAc, and the combined organic layer was washed with saturated Yield: 3.57 g, 95 from rac-6 ; colorless solid; mp NaHCO3 and brine, dried over anhydrous MgSO4, filtered, 32-33 ; α 25D1.78 c0.5, MeOH, 70 e.e. for R and concentrated. Purification of the crude product by -2e . IR KBr : cm1 3303 N-H , 3031 Ar, C-H , 2917 silica gel column chromatographyn-hexane/EtOAc, 4/1, v/ -CH3 , 2853 -CH2- , 1720 OCO 1543, 1455 Ar, CC , 1242 C-O , 747, 697 Ar, C-H . 1H tively. Enantiomeric excesses of R -1a and S -3a were NMR 400 MHz, TMS/CDCl3 : δ 0.88 t, J6.9 Hz, 3H, determined by GC from the corresponding 5. Absolute -CH2CH3 , 1.25 m, 14H, -CH2-7 , 1.53 m, 4H, -CH2CH configuration of all compounds was determined from the CH2- , 1.62, 1.70m, 2H, -NHC O corresponding 5 compared with the literature data.
O CH3 , 2.20 m, 2H, -NHC 4.40d, J5.7 Hz, 2H, PhCH 2NHCO - , 4.85quin, J Colorless solid; mp74-75 6.9, 5.7 Hz, 1H, -CH2CH OAc CH2- , 6.12 br s, 1H, NH , MeOH, 74 e.e. for S -3a . IR KBr : cm1 3289 O-H, 7.26 m, 3H, Ph , 7.31 m, 2H, Ph . 13C NMR 100 MHz, N-H , 3099 N-H , 2955 -CH3 , 2923 -CH2- , 2873 -CH3 , TMS/CDCl3 : δ 14.0 -CH2CH3 , 21.1 -OC 2848 -CH2- , 1639 NHCO . 1H NMR 400 MHz, TMS/ O CH2CH2- , 22.6, 25.2, 29.2, 29.4, 29.5, 31.8 CDCl3 : δ 0.88 t, J7.5 Hz, 3H, -CH 2CH3 , 1.23 m, 12H, , 33.4, 34.0-CH 2CHOAc , 1.47 m, 4H, -CH2CH OH CH2- , 1.75 m, 2H, O CH2- , 43.4 PhCH2NHC O - , 73.6 -CH2CH OAc O CH2CH2- , 1.86 br s, 1H, OH , 2.23 m, 2H, CH2- , 127.3, 127.7, 128.5, 138.3Ph4 CH2- , 2.81d, J5.0 Hz, 3H, CH 3NHCO CH3 , 172.4-NHC O calcd. for C23H37NO3 3.58 m, 1H, -CH2CH OH CH2- , 5.55 br s, 1H, NH . 13C , 375.2773; foundM , 375.27488.
NMR100 MHz, TMS/CDCl 3 : δ 14.1-CH 2CH3 , 21.6-NHC CH2CH2- , 22.7-CH 2- , 25.7-CH 2CHOH 2.3 General procedure for Novozym 435-catalyzed meth- O - , 29.3, 29.6, 29.7, 31.9 -CH2-4 O CH2- , 36.7, 37.6 -CH2CH OH CH2- , In a typical experiment Table 1, Entry 3 , racemic N- CH2- , 173.7-NHC O methy-5-acetoxytridecanamide rac-1a 1.0 mmol, 0.29 calcd. for C14H30NO2 MH , 244.2277; found MH g , methanol3.0 mmol, 0.10 g , and Novozym 4350.4 g in cyclohexane 20 mL was stirred at 80 for 96 h, then filtered to remove Novozym 435, and concentrated. Purifi- Colorless solid; mp76-77 cation of the crude product by silica gel column chroma- MeOH, 85 e.e. for S -3b . IR KBr : cm1 3286 O-H, tography n-hexane/EtOAc, 1:1, v/v gave R -N-methyl- N-H , 2919 -CH3 , 2848 -CH2- , 1635 NHCO Table 1 Effect of amount of Novozym 435 using rac-1aa).
Yield [%] / Enantiomeric excess [% e.e.]b) a) rac-1a: 1.0 mmol, MeOH: 3.0 mmol, Cy-hexane: 20 mL, 80℃, 96 h
b) Determined by GC using InertCap CHIRAMIX column.
J. Oleo Sci. 64, (11) 1213-1226 (2015)
Preparation of optically active δ-tri- and δ-tetradecalactones 400 MHz, TMS/CDCl 3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 0.92 t, J7.4 Hz, 3H, -CH 2CH3 , 1.27 m, 12H, -CH2-6 Colorless solid; mp71-72 1.43 m, 4H, -CH2-2 , 1.51 sext, J7.4 Hz, 3H, MeOH, 89 e.e. for S -3e . IR KBr : cm1 3297 O-H, CH3CH2CH2- , 1.75m, 2H, -NHC O CH2CH2- , 2.22t, J N-H , 3031 Ar, C-H , 2919 -CH3 , 2848 -CH2- , 1639 O CH2- , 2.53 br s, 1H, OH , 3.20 , 1556, 1456 Ar, CC , 730, 696 Ar, C-H . 1H q, J7.4, 5.7 Hz, 2H, -CH 2CH2NHC NMR 400 MHz, TMS/CDCl3 : δ 0.88 t, J6.9 Hz, 3H, CH2- , 5.93br s, 1H, NH . 13C NMR100 MHz, -CH2CH3 , 1.26 m, 11H, -CH2-6 , 1.40 m, 4H, -CH2CH TMS/CDCl3 : δ 11.3 CH3CH2CH2- , 14.0 -CH2CH3 , 21.6 OH CH2- , 1.47 m, 1H, -CH2CH OH CH2CH2- , 1.75 m, O CH2CH2- , 22.6 -CH2- , 22.8 CH3CH2CH2- , CH2CH2- , 2.24t, J7.4 Hz, 2H, -NHC 25.7, 29.2, 29.5, 29.7, 31.8 -CH2-5 O CH2- , 2.30 br s, 1H, OH , 3.55 m, 1H, -CH2CH OH CH2- , 36.6 -CH2CH OH CH2- , 37.5 -CH2CH OH CH2- , CH2- , 4.40 d, J 5.7 Hz, 2H, PhCH2NHCO 41.2 CH3CH2CH2NHC O - , 71.1 -CH2CH OH CH2- , 1H, NH , 7.26m, 3H, Ph O - . HRMS FD calcd. for C16H34NO2 M MHz, TMS/CDCl3 : δ 14.1 -CH2CH3 , 21.6 -NHC H , 272.2590; foundMH , 272.26113.
CH2CH2- , 22.6 -CH2- , 25.7 -CH2CH OH CH2CH2- , 29.2, 29.6, 29.7, 31.8 -CH2-4 Colorless solid; mp58-59 -CH2CH OH CH2- , 37.5 -CH2CH OH CH2- , 43.5 MeOH, 49 e.e. for S -3c . IR KBr : cm1 3285 O-H, O - , 71.2 -CH2CH OH CH2- , 127.4, N-H , 2918 -CH3 , 2850 -CH2- , 1635 NHCO 127.7, 128.6, 138.3 Ph4 400 MHz, TMS/CDCl 3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , FD calcd. for C20H33NO2 M , 319.2511; found M , 1.14 d, J6.3 Hz, 6H, CH3 2CH- , 1.27 m, 11H, -CH2- 6 , 1.43 m, 4H, -CH2CH OH CH2- , 1.48 m, 1H, -CH2CH OH CH2CH2- , 1.74 quin, J7.5 Hz, 2H, -NHC Colorless solid; mp79-80 CH2CH2- , 2.18 t, J7.4 Hz, 2H, -NHC MeOH, 71 e.e. for S -4a . IR KBr : cm1 3294 O-H, , 3.75m, 1H, -CH 2CHOH CH2- , 4.07quin, N-H , 3101 N-H , 2954 -CH3 , 2922 -CH2- , 2872 -CH3 , J6.3, 6.3, 6.9 Hz, 1H, CH3 2CH- , 5.73 br s, 1H, NH . 2848 -CH2- , 1639 NHCO . 1H NMR 400 MHz, TMS/ 13C NMR 100 MHz, TMS/CDCl3 : δ 14.0 -CH2CH3 , 21.6 CDCl3 : δ 0.88 t, J7.0 Hz, 3H, -CH 2CH3 , 1.22 m, 14H, O CH2CH2- , 22.6 -CH2- , 22.7 CH3 2CH- , , 1.47 m, 4H, -CH2CH OH CH2- , 1.76 m, 2H, CH2CH2- , 29.2, 29.5, 29.6, 31.8-CH 2- O CH2CH2- , 1.86 br s, 1H, OH , 2.23 m, 2H, O CH2- , 36.6 -CH2CH OH CH2- , 37.5 CH2- , 2.81d, J4.5 Hz, 3H, CH 3NHCO -CH2CH OH CH2- , 41.2 CH3 2CH- , 71.2 -CH2CH OH 3.59 m, 1H, -CH2CH OH CH2- , 5.54 br s, 1H, NH . 13C CH2- , 172.3 -NHC O - . HRMS FD calcd. for NMR100 MHz, TMS/CDCl 3 : δ 14.1-CH 2CH3 , 21.6-NHC , 272.2590; foundMH , 272.25768.
CH2CH2- , 22.7-CH 2- , 25.7-CH 2CHOH O - , 29.3, 29.5, 29.6, 29.7, 31.9 -CH2- Colorless solid; mp86-87 O CH2- , 36.7, 37.6 -CH2CH OH CH2- , MeOH, 91 e.e. for S -3d . IR KBr : cm1 3300 O-H, CH2- , 173.7-NHC O N-H , 2919 -CH3 , 2850 -CH2- , 1637 NHCO calcd. for C15H32NO2 MH , 258.2433; found MH 400 MHz, TMS/CDCl 3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 1.14 m, 3H, -CH2CH CH2- NHC , 1.34, 1.37 m, 1H, -CH2- at cHx , 1.43 m, 4H, Colorless solid; mp80-81 -CH2CH OH CH2- , 1.50 m, 1H, -CH2CH OH CH2CH2- , MeOH, 72 e.e. for S -4b . IR KBr : cm1 3284 O-H, 1.62 m, 1H, -CH2CH CH2- NHC N-H , 2920 -CH3 , 2848 -CH2- , 1636 NHCO -CH2CH2CH CH2- NHC O - , 1.75 m, 2H, -NHC 400 MHz, TMS/CDCl 3 : δ 0.88 t, J6.9 Hz, 3H, -CH 2CH3 , CH2CH2- , 1.90d, J12.0 Hz, 2H, -CH 2CH2CHCH 2- NHC 0.92 t, J7.5 Hz, 3H, CH 3CH2- , 1.26 m, 14H, -CH2-7 O - , 2.19 m, 2H, -NHC O CH2- , 2.34 br s, 1H, 1.43 m, 4H, -CH2CH OH CH2- , 1.51 m, 2H, CH3CH2CH2- , OH , 3.58m, 1H, -CH 2CHOH CH2- , 3.76m, 1H, -CH 2CH O CH2CH2- , 2.22 t, J7.5 Hz, 2H, CH2- , 2.42 br s, 1H, OH , 3.20 q, J6.9 Hz, MHz, TMS/CDCl3 : δ 14.0 -CH2CH3 , 21.6 -NHC O - , 3.58 m, 1H, -CH2CH OH CH2CH2- , 22.6 -CH2- , 24.8 -CH2CH2CH CH2- NHC CH2- , 5.86 br s, 1H, NH . 13C NMR 100 MHz, TMS/CDCl3 : 2- at cHx , 25.7, 29.2, 29.5, 29.7, 31.8 11.5 CH3CH2CH2- , 14.2 -CH2CH3 , 21.7 -NHC 33.1 -CH2CH CH2- NHC CH2CH2- , 22.7 -CH2- , 22.9 CH3CH2CH2- , 25.8, 29.4, 36.6, 37.5 -CH2CH OH CH2- , 48.1 -CH2CH CH2- NHC 29.6, 29.7, 29.8, 32.0 -CH2-6 O - , 71.1 -CH2CH OH CH2- , 172.2 -NHC 36.8, 37.7 -CH2CH OH CH2- , 41.3 CH3CH2CH2- , 71.3 HRMS FD calcd. for C19H38NO2 MH , 312.2903; found -CH2CH OH CH2- , 173.3 -NHC , 312.29382.
calcd. for C17H36NO2 MH , 286.2746; found MH J. Oleo Sci. 64, (11) 1213-1226 (2015)
Y. Shimotori, M. Hoshi and H. Okabe et al. s, 1H, NH , 7.27 m, 3H, Ph , 7.32 m, 2H, Ph . 13C NMR 2.3.8 S -N-iso-Propyl-5-hydroxytetradecanamide S -4c 100 MHz, TMS/CDCl3 : δ 14.1 -CH2CH3 , 21.6 -NHC Colorless solid; mp65-66 O CH2CH2- , 22.7, 25.7, 29.3, 29.5, 29.6, 29.7, 31.9-CH 2- MeOH, 70 e.e. for S -4c . IR KBr : cm1 3284 O-H, O CH2- , 36.6, 37.5 -CH2CH OH CH2- , N-H , 2919 -CH3 , 2850 -CH2- , 1634 NHCO O - , 71.2 -CH2CH OH CH2- , 127.5, 400 MHz, TMS/CDCl 3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , 127.8, 128.7, 138.3 Ph4 1.14 d, J6.3 Hz, 6H, FD calcd. for C21H35NO2 M , 333.2668; found M , , 1.43 m, 4H, -CH2CH OH CH2- , 1.49 m, 1H, -CH2CH OH CH2CH2- , 1.74 quin, J7.5 Hz, 2H, 2.3.11 δ-Tridecalactone 5 O CH2CH2- , 2.18 m, 2H, -NHC Yield: 0.08 g, 79 S -5 , 0.04 g, 76 R -5 ; color- m, 1H, -CH2CH OH CH2- , 4.08 m, 1H, CH3 2CHNHC less oil. Enantiomeric excess determined by GC on an In- O - , 5.47 br s, 1H, NH . 13C NMR 100 MHz, TMS/ ertCap CHIRAMIX 30 m0.25 mm i.d. 0.25 μm film thick - CDCl3 : δ 14.2-CH 2CH3 , 21.6-NHC O ness column, temperature: 150 isothermal , flow rate: -CH2- , 22.9 CH3 2CHNHC O - , 25.8 -CH2CH OH 2.0 mL/min, t 128.518 min, CH2CH2- , 29.4, 29.7, 29.8, 32.0 -CH2-4 35.4 c 0.2, MeOH, S -5 with 99 e.e., lit α 20D35.0 O CH2- , 36.8, 37.6 -CH2CH OH CH2- , 41.3 CH3 2 c1.38, CHCl 3, 98 e.e. 42 , α 20D38.0 O - , 71.3 -CH2CH OH CH2- , 172.3 -NHC MeOH, R -5 with 99 e.e., lit α D45.2 c1.58, THF, O - . HRMS FD calcd. for C17H36NO2 MH : cm1 2953-CH 3 , 2926-CH 2- , , 286.27138.
2872-CH 3 , 2855-CH 2- , 1734OC O 2.3.9 S -N-Cyclohexyl-5-hydroxytetradecanamide S -4d NMR 400 MHz, TMS/CDCl3 : δ 0.88 t, J7.0 Hz, 3H, Colorless solid; mp78-79 -CH2CH3 , 1.28m, 10H, -CH 2-5 , 1.52m, 4H, -CH 2-2 MeOH, 71 e.e. for S -4d . IR KBr : cm1 3301 O-H, 1.68 m, 1H, -CH2CH CH2- OC N-H , 2918 -CH3 , 2849 -CH2- , 1636 NHCO -CH2CH2CH CH2- OC O - , 2.51 m, 2H, -CH2C 400 MHz, TMS/CDCl 3 : δ 0.88t, J6.9 Hz, 3H, -CH 2CH3 , O- , 4.28 m, 1H, -CH2CH CH2- OC 1.13 m, 3H, -CH2CH CH2- NHC MHz, TMS/CDCl3 : δ 14.1 -CH2CH3 , 18.5 -CH2CH2CH , 1.35, 1.37 m, 1H, -CH2- at cHx , 1.43 m, 4H, O - , 22.6, 24.9, 27.8 -CH2-3 -CH2CH OH CH2- , 1.49 m, 1H, -CH2CH OH CH2CH2- , -CH2CH2CH3 , 29.3 -CH2CH3 , 29.4 -CH2- , 29.5 -CH2CH 1.62 m, 1H, -CH2CH CH2- NHC O - , 31.8 -CH2CH CH2- OC -CH2CH2CH CH2- NHC O - , 1.72 m, 1H, -CH2CH2CH O O- , 80.6 -CH2CH CH2- OC O - , 1.75 quin, J8.0, 7.5 Hz, 2H, -NHC O O- . HRMS FI calcd. for C13H24O2 M O CH2CH2- , 1.91 d, J12.0 Hz, 2H, -CH 2CH2CH , 212.17757.
O - , 2.19 m, 2H, -NHC 2.3.12 δ-Tetradecalactone 6 m, 1H, -CH2CH OH CH2- , 3.76 m, 1H, -CH2CH CH2- Yield: 0.06 g, 81 S -6 , 0.03 g, 78 R -6 ; color- - , 5.52br s, 1H, NH . 13C NMR100 MHz, TMS/ less oil. Enantiomeric excess determined by GC on an In- CDCl3 : δ 14.1-CH 2CH3 , 21.6-NHC O ertCap CHIRAMIX 30 m0.25 mm i.d. 0.25 μm film thick - -CH2- , 24.8 -CH2CH2CH CH2- NHC ness column, temperature: 160 isothermal , flow rate: -CH2CH2CH2CH CH2- NHC 2.0 mL/min, t 117.444 min, 29.3, 29.5, 29.6, 29.7, 31.9-CH 2-5 , 33.2-CH 2CHCH 2- c 1.0, MeOH, S -6 with 99 e.e. , α 20D O CH2- , 36.6, 37.5 -CH2CH 40.2 c 1.0, MeOH, R -6 with 99 e.e. IR NaCl : cm 1 OH CH2- , 48.1 -CH2CH CH2- NHC 2954 -CH3 , 2925 -CH2- , 2870 -CH3 , 2855 -CH2- , 1734 -CH2CH OH CH2- , 172.1 -NHC . 1H NMR400 MHz, TMS/CDCl 3 : δ calcd. for C20H40NO2 MH , 326.3059; found MH 0.88 t, J6.8 Hz, 3H, -CH 2CH3 , 1.28 m, 12H, -CH2-6 1.54 m, 4H, -CH2-2 , 1.70 m, 1H, -CH2CH CH2- OC O - , 1.87 m, 3H, -CH2CH2CH CH2- OC Colorless solid; mp74-75 O- , 4.28 1H, m, -CH2CH CH2- OCO MeOH, 79 e.e. for S -4e . IR KBr : cm1 3296 O-H, 13C NMR 100 MHz, TMS/CDCl3 : δ 14.1 -CH2CH3 , 18.5 N-H , 3030 Ar, C-H , 2919 -CH3 , 2848 -CH2- , 1639 -CH 2CH2CHCH 2- OCO - , 22.7, 24.9, 27.8, 29.3-CH 2- , 1555, 1457 Ar, CC , 729, 695 Ar, C-H . 1H , 29.4 -CH2CH2CH3 , 29.5 -CH2CH3 , 29.5 -CH2- , NMR 400 MHz, TMS/CDCl3 : δ 0.88 t, J6.9 Hz, 3H, 31.9 -CH2CH CH2- OC O - , 35.9 -CH2CH CH2- OC -CH2CH3 , 1.26 m, 13H, -CH2-7 , 1.41 m, 4H, -CH2CH O - , 80.6 -CH2CH CH2- OC OH CH2- , 1.49 m, 1H, -CH2CH OH CH2CH2- , 1.77 m, OCH3 . HRMS FI calcd. for C14H26O2 M , 226.1933; found O CH2CH2- , 2.09 br s, 1H, OH , 2.25 t, J , 226.19376.
O CH2- , 3.57 m, 1H, -CH2CH OH CH2- , 4.42d, J5.7 Hz, 2H, PhCH 2NHCO J. Oleo Sci. 64, (11) 1213-1226 (2015)
Preparation of optically active δ-tri- and δ-tetradecalactones 2.4 Cyclohexylamine additive Novozym 435-catalyzed enantioselectivity was shown, seven days were required to methanolysis of rac-1a and rac-2a40 reach about 50 conversion. In this paper, we aimed at In a typical experiment Table 5, Entry 9 , a mixture of synthesis of optical activity δ-tri- and δ-tetradecalactones. racemic N-methyl-5-acetoxytridecanamide 1.0 mmol, 0.29 The amount of Novozym 435 added was investigated for g , methanol 3.0 mmol, 0.10 g , cyclohexylamine 2.0 the purpose of shortening the reaction time and the effect mmol, 0.20 g , Novozym 435 0.4 g in the mixed solvent 20 on enantioselectivity Scheme 1, Table 1 . Racemic N- mL, cyclohexane/CPME, 4/1, v/v were stirred at 80 for methyl-5-acetoxytridecanamide rac-1a was used as a 96 h. Novozym 435 was removed by filtration, and the re- substrate, and methanolysis was performed in cyclohexane maining solution was concentrated. Purification of the adding 0.2-0.6 g of Novozym 435 for four days. When 0.3, crude product by silica gel column chromatography n- 0.4, or 0.5 g was added, a great difference in the conversion hexane/EtOAc, 1/1, v/v gave the mixture of R -1a, S rate was not observed Table 1, Entries 2, 3, and 4 . On the . The crude mixture ofR other hand, in the case of 0.2 g, the conversion was low, -3d was hydrolyzed with Na2CO32.0 g and it was high with 0.6 g Table 1, Entries 1 and 5 . With 20 mL at 80 for 5 h, cooled, and then concentrated. 0.2 g of Novozym 435, although there were only small Water 50 mL and CHCl3 20 mL were added, and the amounts ofS -5, the reaction progressed with organic layer was separated. The aqueous phase was ex- about 90 enantioselectivity Table 1, Entry 1 . R -1a tracted with CHCl3, and the combined organic layer was showed 89 enantiomeric excess using 0.6 g Novozym 435 washed with brine, dried over anhydrous MgSO , Entry 5 . When 0.3-0.5 g of Novozym 435 was and concentrated. Purification of the crude product by used, methanolysis progressed with about 80 enantiose - silica gel column chromatographyn-hexane/EtOAc, 1/1, v/ lectivity. It was seemed that S -3a andS 80 enantiomeric excess, respectively, in 50 conversion lactonization method and determination of enantiomeric with addition of 0.2 g and 0.6 g. Based on these results, al- excess and absolute configuration were described above.
though the amount of Novozym 435 added affects the con-version rate, it does not affect enantioselectivity greatly. The yields of S -3a and S -5 increased with the amount of Novozym 435, and the comparably long reaction time 3 Results and discussion
was required. It was seemed that substrate affinity of 3.1 Effect of amount of Novozym 435 on reactivity and Novozym 435 to rac-1a was low. As the amount of Novozym 435 was increased, the amount of substrate in- We previously reported synthesis of optical activity corporated into the active site in the enzyme increased, δ-hexadecalactone by lipase-catalyzed resolution40 . Ro- and the yields of S -3a and S -5 were increased. drigues et al. reported that Novozym 435 showed high However, inR -5, an average high en- enzyme activity for methanolysis, and we used methanol as antiomeric excess was shown in the case of 0.4 g. There- proton donor44 . Methanolysis was performed using 0.4 g fore, it was determined that the addition of 0.4 g Novozym Novozym 435 to 1.0 mmol substrate. Although about 80 435 to 1.0 mmol substrate was optimal.
Scheme 1 Novozym 435-catalyzed kinetic resolution of rac-1 and rac-2.
J. Oleo Sci. 64, (11) 1213-1226 (2015)
Y. Shimotori, M. Hoshi and H. Okabe et al. 3.2 Effect of solvent and structure on enantioselectivity excesses of S -3a and S -5 were high. From these results, The effect of a solvent on enantioselectivity and conver- it seemed that the mixed solvent of cyclohexane and CMPE sion was observed using rac-1a as a substrate Table 2 . produced high conversion and enantioselectivity for Methanolysis was performed for four days using various Novozym 435-catalyzed methanolysis of rac-1 and rac-2 at solvents. Methanolysis progressed in almost all solvents except THF, acetone, and phosphate buffer Table 2, The effect of an R2 group on the reactivity and enanti- Entries 6-8 . Permittivity is high for these three solvents oselectivity was confirmed Table 3 . Rac-1 and rac-2 were compared with the solvent in which a reaction progressed. hydrolyzed with Novozym 435 in cyclohexane for 4 and 5 Enzyme is required free water to exhibit activity45 . The re- days, respectively. 4 and 5 days were required to reach lationship between water activity and enzyme activity was about 50 conversions for Novozym 435-catalyzed metha - reported by Degn et al.46 It was assumed that because nolysis of rac-1a and rac-2a, respectively. The substrate these three solvent with high permittivity took free water possessed long chain at R1 group took long reaction time from enzyme, Novozym 435 was deactivated, and methano- for Novozym 435-catalyzed methanolysis40 . The reaction lysis was not progressed. In the case of n-hexane and cy- time of rac-1a-e was 4 days, and rac-2a-e was 5 days to clohexane, the conversion was high compared with ether confirm the effect of R2 group. In the case of N-alkyl-5-ace- and toluene. The enantioselectivity was high, but the reac- toxytridecanamides rac-1 showed high conversion com- tion was slowest in the case using toluene. These indicated pared with those with cHx and Bn groups. It seemed that a that Novozym 435-catalyzed methanolysis of rac-1a was substrate with a small R2 group has high reactivity for slow in high polar solvent compared with in low polar Novozym 435-catalyzed methanolysis. The low conversion solvent. When n-hexane and cyclohexane were compared, substrates rac-1b, d and e gave S -3 and S -5 with the conversion was high using cyclohexane, although n- higher enantiomeric excesses than the high conversion hexane showed a slightly higher enantioselectivity than cy- substrates rac-1a and c . Conversely, rac-1 with Me and clohexane Table 2, Entries 1 and 2 . i-Pr2O and CPME i-Pr groups afforded higher enantiomeric excesses of R also indicated the same tendency Table 2, Entries 3 and -1. When the Me group was compared with the i-Pr group, 4 . There are no great differences in the permittivity there were no great differences in the enantiomeric ex- among these solvents, such as n-hexane and cyclohexane cesses of R -1. However, the Me group showed higher en- or i-Pr2O and CPME. These results showed that the metha- antiomeric excesses for both S -3 and S -5. From these nolysis at 80 was faster than that at 60 . In other words, results, it was assumed that the Me group was optimal as it is expected to shorten the reaction time at 80. The en - an R2 group, considering the conversion and respective en- antiomeric excesses of S -3a andS -5 produced with cy- antiomeric excesses Table 3, Entry 1 . On the other hand, clohexane or CPME were slightly low relative to these with when using N-alkyl-5-acetoxytetradecanamides rac-2 n-hexane or i-Pr2O, but unreacted R -1a had high enen- with n-C9H19 as a substrate, great differences in the conver- tiomeric excess. The enantiomeric excess of R -1a was sion for all substrates rac-2a, b, d and e except rac-2c high although the conversion using cyclohexane was higher were not observed, and rac-2c with i-Pr as R2 group than that using CPME. Conversely, CPME showed low con- showed low conversion. In rac-1, rac-1b, which has a com- version compared with cyclohexane, but the enantiomeric paratively small n-Pr group showed low conversion as with Table 2 Effect of solvent using rac-1aa).
Yield [%] / Enantiomeric excess [% e.e.]b) Phosphate buffer (pH=7) a) rac-1a: 1.0 mmol, MeOH: 3.0 mmol, Novozym 435: 0.4 g, Solvent: 20 mL, 96 h
b) Determined by GC using InertCap CHIRAMIX column.
c) Ref. 47 d) Ref. 48 e) Ref. 49 f) Ref. 50 g) Ref. 51 J. Oleo Sci. 64, (11) 1213-1226 (2015)
Preparation of optically active δ-tri- and δ-tetradecalactones Table 3 Effect of R2 groupa).
Yield [%] / Enantimeric excess [% e.e.]b) (R)-1 and 2
(S)-3 and 4
(S)-5 and 6
a) rac-1 and 2: 1.0 mmol, MeOH: 3.0 mmol, Novozym 435: 0.4 g, Cy-hexane: 20 mL, 80℃
b) Determined by GC using InertCap CHIRAMIX column.
rac-1d and rac-1e Table 3, Entry 3 . These results show used. When CPME was used as the solvent, Novozym only that the bulkiness of R2 group does not affect conver- 435-catalyzed methanolysis of rac-1a progressed with the sion. Lemke et al. reported that enzyme recognizes the highest enantioselectivity, although the mixed solvent of shape of a substrate molecule, not the size52 . R2 groups in cyclohexane/CPME25:75 gave the highest enantiomeric the substrates used in this paper had various shapes. It was excess ofS -3a Table 4, Entry 17 . From these results, it assumed that Novozym 435 had high substrate specificity was assumed that the mixed solvent of cyclohexane/CPME for all substrates except rac-2c because there was no great 80:20 or 75:25 was suitable because these solvents gave difference in the conversions and enantiomeric excesses shorter reaction times with only a slight decrease of enan- among all substrates except rac-2c with a i-Pr group. In tioselectivity Table 4, Entries 9 and 11 . Similarly, CPME other words, Novozym 435 exhibited low substrate affinity was suitable because although it required longer reaction and selectivity for rac-2c. Rac-2a with a Me group gave R time, but it showed high enantioselectivity Table 4, Entry -6 with high enantiomeric excesses, although no 17 . In the case of rac-2a, the mixed solvent which includ- great difference in the results among all rac-2 except ed 5-25 CPME did not affect the conversion compared rac-2c was observed, and rac-2a was the optimal substrate with cyclohexane alone, and it had the same tendency as in rac-2. When rac-1a is compared to rac-2a, the substrate rac-1aTable 4, Entries 2, 4, 6, 8, 10 and 12 affinity of Novozym 435 for rac-1a was higher because the with which CPME was mixed up to 25 didn t have a great reaction time of rac-1a required until the conversion effect on enantioselectivity. When optically active reached about 50 was shorter than that of rac-2a. In δ-hexadecalactone was synthesized by the same method, contrast, the substrate selectivity of Novozym 435 for the ratio of cyclohexane to CPME widely affected the con- rac-2a was slightly high compared with that of rac-1a.
version and enantioselectivity40 . However, it cannot be said When rac-1a was hydrolyzed using Novozym 435, cyclo- that the mixing ratio greatly affected the conversion and hexane gave a high conversion with a short reaction time enantioselectivity of rac-1a and rac-2a.
and CPME showed high enantioselectivity Table 2 . It seemed that the optimal conditions, a short reaction time 3.3 Amine added Novozym 435-catalyzed methanolysis with high enantioselectivity was obtained by using mixture of these two solvents Table 4 . The solvent in which δ-hexadecalactone using Novozym 435-catalyzed enanti- CPME was mixed at 5-25 with cyclohexane showed oselective methanolysis of N-methyl-5-acetoxyhexadecan- almost the same conversion as using only cyclohexane or amide40 . The addition of two equivalent amounts of cyclo- any more when rac-1a was hydrolyzed as a substrate Table hexylamine to N-methyl-5-acetoxyhexadecanamide 4, Entries 1, 3, 5, 7, 9, and 11 . When a solvent including 5, increased enantioselectivity about 10 relative to the 10, or 15 CPME was used, the enantiomeric excess of S - absence of it. In this investigation, we considered that 3a decreased compared with only cyclohexane Table 4, Novozym 435 catalyzed methanolysis of N-methyl-5-ace- Entries 3, 5, and 7 . The mixed CPME including cyclohex- toxyhexadecanamide enantioselectively to afford optically ane reduced the reaction time until 50 conversion was active N-methyl-5-hydroxyhexadecanamide and subse- reached compared with the case when only CPME was quently intra-esterized it enantioselectively, and catalysis J. Oleo Sci. 64, (11) 1213-1226 (2015)
Y. Shimotori, M. Hoshi and H. Okabe et al. Table 4 Effect of Mixed solventa).
Yield [%] / Enantimeric excess [% e.e.]b) (R)-1 and 2
(S)-3 and 4
(S)-5 and 6
a) rac-1a and 2a: 1.0 mmol, MeOH: 3.0 mmol, Novozym 435: 0.4 g, Solvent: 20 mL, 80℃
b) Determined by GC using InertCap CHIRAMIX column.
of these two reactions at the same time caused a decrease for rac-1a as a substrate Table 5, Entries 5 and 9 . On the of enantioselectivity for the methanolysis of N-methyl- other hand, only cyclohexane and the mixed solvent of cy- 5-acetoxyhexadecanamide. Novozym 435 also catalyzed clohexane/CPME90:10, 85:15, 75:25, or 50:50 gave both the methanolysis and intra-esterification enantioselectively enantiomers R -3a and S -4d with over 90 enantio- for rac-1a and rac-2a at the same time because optically meric excesses for Novozym 435-catalyzed methanolysis of active lactones S -5 and 6 were produced at the metha- rac-2a Table 5, Entries 6, 8, 12 and 14 . These results nolysis and the enantiomeric excesses of lactones were confirmed that addition of cyclohexylamine increased the higher than those of hydroxyamides S -3 and 4 Table enantioselectivity for Novozym 435-catalyzed methanolysis 4 . Therefore, it seemed that addition of cyclohexylamine of rac-1a and rac-2a, like the case of N-methyl-5-acetoxy- increased the enantioselectivity for the Novozym 435-cata- hexadecanamide. The enantiomeric excesses of both enan- lyzed methanolysis of rac-1a and rac-2a Scheme 2, Table tiomers for δ-tri- and δ-tetradecalactones 5 and 6 were 5 . The enantioselectivity of Novozym 435 was increased over 90 without racemization.
by the addition of cyclohexylamine in almost all conditions. The enantiomeric excess improved more than 20 from 3.4 Sensory properties of optically active δ-tri- and Table 5, Entries 3, 11, 13, 14, and 18 . Additionally, it was possible to shorten reaction time until reaching ap- The enantiomers of δ-tri- and δ-tetradecalactone 5 and proximately 50 conversion by 24 hours in many cases. 6 showed different odor characteristics Table 6 . The Whereas all mixed solvents showed about 80 enantiose - odor intensity of the R -enantiomer R -5 was about lectivity without addition of cyclohexylamine, methanolysis two times stronger than that of S -enantiomer S -5 . of mixtures to which cyclohexylamine was added pro- Some differences in odor quality were also detected. The gressed with about 90 enantioselectivity. When only cy- -enantiomer of 5 exhibited a hay-like note. TheS clohexane or the mixed solvent of cyclohexane/CPME antiomer showed some resemblance to a walnut note. In 90:10 or 80:20 was used, both enantiomers R -3a and S - contrast, both 6 exhibited a hay-like note, and there was 3d were obtained with over 90 enantiomeric excesses no great difference of odor quality among each enantiomer -3a showed a somewhat low enantiomeric excess of 6. Additionally, no difference of odor intensity was felt J. Oleo Sci. 64, (11) 1213-1226 (2015)
Preparation of optically active δ-tri- and δ-tetradecalactones Scheme 2 Amine added methanolysis in Novozym 435-catalyzed kinetic resolution.
Table 5 Effect of solvent on cHxNH2 added Novozym 435-catalyzed methanolysisa).
Yield [%] / Enantiomeric excess [% e.e.]b) (R)-3a and 4a
(S)-3a and 4a
(S)-3d and 4d
a) rac-1 and 2: 1.0 mmol, MeOH: 3.0 mmol, cHxNH2: 2.0 mmol, Novozym 435: 0.4 g, Cy-hexane: 20 mL, 80℃
b) Determined by GC using InertCap CHIRAMIX column.
addition of 0.4 g Novozym 435 was suitable for a 1.0 mmol substrate. When cyclohexane was used as the solvent, high conversion was shown in a short time. Methanolysis pro-gressed with high enantioselectivity using CPME. It dif- fered from the preparation of δ-hexadecalactone, and a re- Enantiomers of both δ-tri- and δ-tetradecalactones were markable increase of enantioselectivity for Novozym 435 synthesized with over 90 enantiomeric excesses using was not observed for the mixed solvent of cyclohexane and Novozym 435-catalyzed methanolysis as a key step. The CPME. Addition of cyclohexylamine for Novozym 435-cata- J. Oleo Sci. 64, (11) 1213-1226 (2015)
Y. Shimotori, M. Hoshi and H. Okabe et al. Table 6 Odor properties of optically active δ-tri- and δ-tetradecalactonea).
% e.e.b) / [α]20D (MeOH) Odor propertiesc) Threshold [ppm]d) 99 / +38.0 (c= 0.2) weak, hay-like note 99 / -35.4 (c= 0.2) weak, some reminiscence to walnut 99 / +40.2 (c= 0.2) weak, hay-like note 99 / -40.8 (c= 0.2) weak, hay-like note a) All samples tested were prepared by previous method53).
b) Determined by GC using InertCap CHIMIX column.
c) Odor was evaluated on blotters. Neat samples were taken on blotters.
d) Odor threshold concentrations in 30% ethanol aqueous solution were determined.
lyzed methanolysis of rac-1a and rac-2a increased enanti- 4 Chidley, H. G.; Kulkarni, R. S.; Pujari, K. H.; Giri, A. P.; oselectivity about 10-20 compared with the absence of Gupta, V. S. Spatial and temporal changes in the vola- it, and the reaction time was shortened. Optically active tile profile of Alphonso mango upon exogenous ethyl- δ-tri- and δ-tetradecalactones could also be prepared in ene treatment. Food Chem. 136, 585-594 2013 .
high enantiomeric excess by the use of mixed solvent com- 5 Zhang, B.; Xi, W.; Wei, W.; Shen, J.; Ferguson, I.; Chen, pared with the case when cyclohexane or CPME was used K. Changes in aroma-related volatiles and gene ex- individually. Different odor characteristics were confirmed pression during low temperature storage and subse- for δ-tridecalactone. TheR -enantiomer showed a hay-like quent shelf-life of peach fruit. Postharvest Biol. Tech- note, and the S -enantiomer exhibited some resemblance nol. 60, 7-16 2011 .
to walnuts. However, there was no great difference in odor 6 Laurence, B. R.; Pickett, J. A. erythro-6-Acetoxy- intensity for δ-tri- and δ-tetradecalactones among each en- 5-hexadecanolide, the major component of a mosquito oviposition attractant pheromone. J. Chem. Soc. Chem. Commun. 59-601982 7 Ikan, R.; Gottlieb, R.; Bergmann, E. D.; Ishay, J. The pheromone of the queen of the oriental hornet, Vespa orientalis. J. Insect Physiol. 15, 1709-17121969 We are grateful to the Zeon Corp. for the generous gift of 8 Cossé, A. A.; Bartelt, R. J.; James, D. G.; Petroski, R. J. CPME. Dr. Hidetaka Tsukasa from Toyotama International Identification of a female-specific, antennally active Inc.is kindly acknowledged for the sensory evaluations.
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Arch Dermatol Res (2005)DOI 10.1007/s00403-005-0584-6 A. Barel Æ M. Calomme Æ A. TimchenkoK. De. Paepe Æ N. Demeester Æ V. RogiersP. Clarys Æ D. Vanden Berghe Effect of oral intake of choline-stabilized orthosilicic acid on skin, nailsand hair in women with photodamaged skin Received: 10 January 2005 / Revised: 20 April 2005Accepted: 23 June 2005 Springer-Verlag 2005

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Appendix iV: LiVer-Toxic MedicATions And Herbs The following information is based on an appendix found in The Hepatitis C Help Book and is reprinted with the permission of the publisher, St. Martin's Griffin. There is a great deal of research still to be done to identify those prescription medications, over-the-counter drugs, herbs and chemicals that are liver toxic. Some substances affect everyone negatively, some are dangerous for people who have