Enantioselective synthesis of the ester side chain of homoharringtonine

Abstract

D -Malic acid as chiral starting material, an efficient synthesis of the ester side chain of homoharringtonine has been developed. A cross-metathesis reaction leads to the formation of the key intermediate, which can be converted later by selective hydrogenation to the methyl ester side chain of homoharringtonine and deoxy-homoharringtoine in a total of six steps with 24.5% and 23.5% in yields, respectively.