A synthesis of (−)-sitophilate by utilizing yeast-mediated reduction of an enol ester
作者:Takeshi Sugai、Daisuke Sakuma、Naoki Kobayashi、Hiromichi Ohta
DOI:10.1016/s0040-4020(01)89726-x
日期:1991.8
The microbial reduction of 1'-ethylpropy 2-methyl-3-oxopentanoate, a beta-keto ester possessing bulky substituent, as well as the corresponding enol ester was examined. Epimeric mixture of hydroxy ester, containing (2S,3S)-isomer as the major product (92%e.e., 43%d.e.) was obtained via the reduction of enol ester with growing cells of Pichia farinosa IAM 4682 in 63% yield. The resulting-beta-hydroxy ester was converted to (2S,3R)-isomer (88%e.e., 96%d.e.), of which e.e. was further enhanced by the lipase-catalyzed partial hydrolysis of the corresponding chloroacetate to give (-)-sitophilate, (99%e.e.) an aggregation pheromone of Sitophillus granarius L.