NOVEL CATALYTIC ENANTIOSELECTIVE PROTONATION (PROTON-TRANSFER) IN MICHAEL ADDITION OF BENZENETHIOL TO ALPHA-ACRYLACRYLATES - SYNTHESIS OF (S)-NAPROXEN AND ALPHA-ARYLPROPIONIC ACIDS OR ESTERS

A novel synthesis of optically active 2-phenylpropionic acids or esters via catalytic enantioselective protonation in the Michael addition of benzenethiol to 2-phenylacrylates is described; the synthetic utility is further demonstrated by the asymmetric synthesis of (S)-Naproxen.