(R)-((2-Oxo-4-thiazolidinyl)methyl)triphenylphosphonium Iodide: A Wittlg Reagent for the Synthesis of Cysteine-Derived Alkenes

摘要

(R)-[(2-Oxo-4-thiazolidinyl)methyl]triphenylphosphonium iodide (1), readily prepared in five steps from L-cysteine ethyl ester (39% overall on a 500 g scale), is a useful Wittig reagent for the synthesis of cysteine-derived alkenes such as those found in dipeptide isosteres and peptidomimetics. Preparation of 1 and its use in Wittig olefination reactions with aldehydes is described. The resulting thiazolidinone compounds are readily unmasked to provide the corresponding thiol, symmetrical disulfide, or S-trityl derivatives.