3-Methoxy-1-(tributylstannyl)-1-propene, a versatile vinyltin synthon

Abstract

3-Methoxy-1-(tributylstannyl)-1-propene ( 1) can be readily transformed into the silylated analogue ( 2), which can react both as a vinyltin and as an allylsilane. Thus, transmetallation of 2 with n-butyllithium, followed by quenching with various electrophiles, gives functionalized allylsilanes. Although reagent 2 can react with benzaldehyde as an allylsilane, the diastereoisomeric mixture of monoprotected 1,2-diols ( 14) can be best obtained from 1 by direct lithiation and quenching with benzaldehyde. The use of Lewis acids allows the control of the stereochemistry of the condensations.