Enantioselective Synthesis of Protected α-Hydroxy Aldehydes and Related 1,2-Amino Alcohols. Applications to the Synthesis of (-)-exo- and (-)-endo-Brevicomin

Abstract

Chiral allylic alcohols which were prepared by the addition of functionalized dialkylzincs to α,β-unsaturated aldehydes in good to excellent enantioselectivity, were converted to protected α-hydroxy aldehydes and 1,2-amino alcohols without loss of optical purity. A functionalized α-silyloxy aldehyde prepared in this way was converted to optically pure (-)-exo- and (-)-endo-brevicomin (> 99 % ee).