摘要:
A method of preparing optically active isocoumarin-3-yl-acetic acid derivatives represented by Formula (I): wherein a specific isocoumarin-ketene derivative is subjected to an addition reaction with an optically active alcohol, and then the ester thus obtained is subjected to a hydrolysis reaction. An intermediate for synthesis used therein. A method of preparing isocoumarin-3-yl-acetic acid derivatives represented by Formula (III): wherein a specific isocoumarin derivative is subjected to an addition reaction with carbon monoxide and oxygen in the presence of a transition metal catalyst. An intermediate for synthesis used therein.