摘要:
In the presence of lipase from the yeast Candida cylindracea, partial acetylation of (+/-)-2-[6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl]ethanol with vinyl acetate gives S-(+)-acetate whose alkaline hydrolysis affords (S)-(-)-alcohol. Repeated enzymatic acetylation of the "residual" alcohol up to similar to39% conversion afforded the R-enantiomer. The enantiomeric alcohols were oxidized to (S)- or (R)-aldehydes having the same sign of \alpha\(D) as the original alcohols. These alcohols were converted into S-(+)- and R-(-)-enantiomers of the antioxidant MDL-73404, a hydrophilic analog of alpha-tocopherol.