Water → 1-Phenylethanol, (S)-

Participants

Reaction Conditions

Reaction Steps

In a 300 ml separable flask were put 3 g of Lipase PL of Alcaligenes sp. origin (a product of Meito Sangyo Co., Ltd., hereinafter the same applies) and 50 g of (R,S)-1-phenylethanol, and the mixture was subjected to ultrasonication with the same ultrasonic wave generating equipment as used in Example 1 at room temperature and at 20 kHz for 20 minutes. To the dispersion was added 150 g of tripalmitin, followed by stirring at 85° C. and 100 rpm for 30 hours to carry out interesterification. The water content of the reaction system was 0.05% by weight, and 93% of the lipase particles had a particle size of 15 to 40 μm. Gas chromatographic analysis of the reaction mixture revealed that 46 mol % of (R,S)-1-phenylethanol had been converted to 1-phenylethyl palmitate. To the reaction mixture was added 1500 ml of acetone, followed by cooling to 10° C. Lipase, unreacted tripalmitin, dipalmitin, monopalmitin, and palmitic acid were removed by filtration using Toyo Filter Paper No. 5A, and the filtrate was subjected to simple distillation at 95° C. under reduced pressure of 5 mmHg to give (S)-(-)-phenylethanol (yield: 87%; chemical purity: 99.9%; optical purity: 86.3% ee). The residue, i.e., (R)-(+)-1-phenylethanol palmitic acid ester was alkali-hydrolyzed in the same manner as in Example 1 to obtain (R)-(+)-1-phenylethanol (yield: 82%; chemical purity: 99.5%; optical purity: 98.0% ee).

Provenance & Evidence