Mechanism of Formation of α,β-Unsaturated Esters in the Reaction of Ethyl Mercaptoacetate Dianion with Carbonyl Compounds

Article abstract of DOI:10.1246/bcsj.57.426

Dianion derived fron ethyl mercaptoacetate undergoes aldol type reaction with a carbonyl compounds to give an adduct, which exhibited low diastereoselectivity.However, the adducts obtained by the reaction with a variety of aldehydes were subsequently treated with ethyl chloroformate in the presence of trivalent phosphorus compound to give (E)-isomers of α,β-unsaturated esters in high yields with greater than 85percent stereoselectivity regardless of the stereochemistry of the diastereomers of the adducts.The stereochemical mechanism and application of this reaction were studied in detail.