| 摘要 |
PROBLEM TO BE SOLVED: To provide a method with which a 4-oxochroman-2-carboxylic acid derivative having an optical activity can inexpensively be synthesized and the economical and industrial production thereof can be carried out. SOLUTION: The method is carried out as follows. A 4-oxochromene-2-carboxylic acid derivative represented by general formula (I) (wherein, R<SP>1</SP>means a hydrogen atom, a chlorine atom, a fluorine atom or a 1-6C alkyl group; and R<SP>2</SP>means a hydrogen or a 1-6C alkyl group which may be substituted) is subjected to a reducing reaction with a siloxane derivative and a lower alcohol in the presence of an asymmetric metal complex formed from an optically active phosphine ligand and a copper salt or a tin salt and an alkali metal alkoxide in an organic solvent to thereby produce the optically active 4-oxochroman-2-carboxylic acid derivative represented by general formula (II) äwherein, R<SP>1</SP>and R<SP>2</SP>have each the same meaning as in general formula (I); and * means an asymmetric carbon}. COPYRIGHT: (C)2006,JPO&NCIPI |
