Facile Production Scale Synthesis of ( S )-Taniguchi Lactone: A Precious Building-Block

A cost-efficient and facile synthesis of (S)-4-vinyldihydrofuran-2(3H)-one ((S)-1), better known as (S)-Taniguchi lactone, is described. Racemic Taniguchi lactone rac-1 was ring-opened with (S)-1-benzylmethylamine providing a diastereomeric mixture of hydroxyl-amides. The desired diastereomer (S,S)-2 was isolated by crystallization and subjected to acidic hydrolysis to release enantiopure title compound in good overall yield with an er in excess of 99%. The process was successfully scaled up to kilogram quantities.