Synthesis of trimethyl .alpha.-keto trithioorthoesters and dimethyl .alpha.-keto dithioacetals by reaction of esters with tris(methylthio)methyllithium
摘要:
A complete study has been made of the reaction of tris(methylthio)methyllithium with aromatic, heteroaromatic, and aliphatic esters. It is a one-pot reaction that despite its complexity, and depending on the reagent ratios, the reaction conditions, and the possible use of additional reagents (N-(methylthio)phthalimide or BuLi), can supply easily, in excellent and reproducible yields, the trimethyl alpha-keto trithioorthoesters 3 or, alternatively, the dimethyl a-keto dithioacetals 4. The reaction mechanism has been elucidated.