PROCESS FOR PRODUCING OPTICALLY ACTIVE 3-(4-HYDROXYPHENYL)PROPIONIC ACIDS

摘要

The present invention relates to a process for producing an optically active 3-(4-hydroxyphenyl)propionic acid useful as intermediates for medicines, through short steps in good yield and with high optical purity. More specifically, the present invention relates to a process for producing an optically active 3-(4-hydroxyphenyl)propionic acid of the formula (6): wherein R<2> is an alkyl group; R<5> to R<8> are each independently a hydrogen atom or a substituent; and the symbol * is an chiral carbon atom, or a salt thereof, which comprises reacting a benzaldehyde of the formula (1): wherein R<1> is a protective group; and R<5> to R<8> are each the same as defined above, with a glycolic acid derivative of the formula (2): wherein R<3> is a hydrocarbon group; and R<2> is the same as defined above, hydrolyzing the resulting product to give a cinnamic acid of the formula (4): wherein R<1>, R<2> and R<5> to R<8> are each the same as defined above, or a salt thereof, and subjecting the resulting cinnamic acid (4) or a salt thereof to asymmetric hydrogenation to give an optically active phenylpropionic acid of the formula (5): wherein all the symbols are each the same as defined above, or a salt thereof, followed by deprotection.