Process for the preparation of optically active 4-oxo-1-benzopyran-2-carboxylic acid derivatives and intermediates thereof

摘要

A process for the preparation of optically active 4-oxo-1-benzopyran-2-carboxylic acid derivatives of the formula <IMAGE> wherein X and Y are hydrogen atom, halogen atom or alkyl group, and R1 is hydrogen atom or alkyl group, intermediates thereof, as well as a process for the preparation of the intermediates.