Ueda_2023_J.Oleo.Sci_72_725

The aim of this study was to present a facile protocol for preparation of both enantiomerically pure forms of (Z)-1,5-octadien-3-ol with lipases and to identify the stereochemistry of oyster alcohol from Crassostrea gigas. The asymmetric hydrolysis of (+/-)-(Z)-1,5-octadien-3-yl acetate with CHIRAZYME L-2 afforded the (R)-alcohol with 99% ee in 37.8% conversion. On the other hand, the first asymmetric acylation of the alkadienol with lipase PS recovered the (S)-alcohol with 79.5% ee in 47.8% conversion. Then, the second asymmetric acylation of the recovered (S)-alcohol with lipase PS gave the remaining (S)alcohol with 99% ee in 14.1% conversion. Thus, we have successfully prepared both enantiomerically pure forms of (Z)-1,5-octadien-3-ol with high ee (99%) separately. On the other hand, oyster alcohol in the extract from C. gigas was purified by silica gel column chromatography and the structure was confirmed by (1)H- and (13)C-nuclear magnetic resonance spectra. Furthermore, the stereochemistry of oyster alcohol was decided as the (R)-form from the specific rotation and its optical purities were determined as 20.45 +/- 0.2% ee by a chiral gas chromatograph/mass spectrometry for the first time.