Preparation of γ-siloxyallyltributylstannanes and their use in the synthesis of (±)-1-deoxy-6,8a-di-epi-castanospermine

Abstract

γ-Siloxyallyltributylstannanes were selectively obtained as E or Z isomers from β-tributylstannylacrolein upon reaction with lithium or magnesium alkylcyanocuprates. The ability of the reagents to give a high syn selectivity when added to iminium salts has been used for the efficient synthesis of (±)-1-deoxy-6,8a-di-epi-castanospermine from succinimide. The key step of the synthesis was the allylstannation of the N-allyliminium intermediate followed by ring closing metathesis.