Highly Enantioselective Synthesis of Propargylic Alcohols by Way of the Asymmetric Aldol Reaction

Abstract
In the presence of a catalytic amount of chiral diamine-coordinated tin(II) triflate, acetylenic aldehydes enantioselectively react with silyl enol ethers of thioesters to afford the corresponding aldol-type adducts, propargylic alcohols, in high yields. The products are easily converted to the corresponding optically active allene derivatives via effective chiral transfer.