A regiocontrolled synthesis of allylstannanes
Abstract
β-Stannyl ester enolates react with aldehydes with fairly high stereoselectivity, the isomeric enolates (4) and (2) respectively giving as major products the allyl hydroxy-stannylbutanoates (6) and (7) with opposite aldol relative stereochemistry. These aldols can be converted stereospecifically (steric and reactivity effects allowing) into the allylstannanes (13) and (14). The cis allylstannane (14aa) is stable to isomerisation in non-polar solvents.