Highly Enantioselective Reduction of 3-Chloro-2-oxoalkanoates with Fermenting Bakers' Yeast. A New Synthesis of Optically Active 3-Chloro-2-hydroxyalkanoates and Glycidic Esters

Article abstract of DOI:10.1021/jo00054a036

Reduction of 3-chloro-2-oxoalkanoic esters with fermenting bakers' yeast gave optically active 3-chloro-2-hydroxyalkanoic esters 2 (anti(2S,3R)/syn(2S,3S) = 52:48-90:10) in 50-85percent yields with > 95percent ee except for 43percent ee of ethyl syn-(2S,3S)-3-chloro-2-hydroxy-4-phenylbutanoate (2j).Compounds 2 were treated with NaOEt to give (E)-(2R,3S)-2,3-epoxyalkanoates 3 in 30-66percent yields with 44-64percent ee.Optically active 2,3-epoxy alcohols (cis-23, trans-23, and trans-25), key intermediates for the syntheses of (-)-disparlure (4), mosquito pheromone (5), and a component of passion fruit flavor (6), were prepared with more than 86percent ee in high yields.