Optically active indolidine derivative and its production

PURPOSE: To obtain the subject derivative having high optical purity due to no side reaction under mild conditions and useful as a synthetic intermediate, etc., for synthetic antitumor agents, etc., by reacting a specific racemic modifica tion with an enzyme, etc., derived from the genus Aspergillus. CONSTITUTION: The objective derivative of formula II is obtained by reacting a racemic modification of ethyl-2-acyloxy-2-[6-cyano1,1-(ethylenedioxy)-5- oxo-1,2,3,5-tetrahydroindolizin-7-yl]butanoate [preferably at 0.1-0.2wt.% concentration] with at least one kind of enzyme selected from the group consisting of enzymes derived from the genus Aspergillus, microbial cells of microorganisms belonging to the genus Aspergillus, its cultured mixture and theirs fractionated materials, preferably in an amount of 1-3 times by weight based on the racemic modification. COPYRIGHT: (C)1993,JPO&Japio