Stereoselective approach to (2R,3S)- and (2R,3R)-1,2-(cyclohexylidenedioxy)hept-6-en-3-ol by microbial reduction

Among twelve incubated whole-cell yeast strains, two were found to selectively reduce (R)-1,2-(cyclohexylidenedioxy)hept-6-en-3-one, which was derived from d-mannitol. Pichia minuta JCM 3622 and Rhodotorula mucilaginosa NBRC 0889 afforded (2R,3S)-form (97% diastereomeric purity) and (2R,3R)-form (89% diastereomeric purity) of 1,2-(cyclohexylidenedioxy)hept-6-en-3-ols, respectively. As discussed above, the complementary yeast-mediated reduction provided the two diastereomeric glycerol derivatives in high enantiomeric excess.