A method of preparing optically active isocoumarin-3-yl-acetic acid derivatives
represented by Formula (I):
##STR1##
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):
##STR2##
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.
