Deracemization of thiol esters of α-arylpropionic acids
摘要:
Racemic thiol esters of alpha-arylpropionic acids were deracemized by a procedure which featured deprotonation with LDA or KHMDS, transformation into the TMS or TBDMS enol ethers, and enantioselective protonation of the silyl enol ethers using (R)-1,1'-bi-2-naphthol/SnC1(4). Oxidative hydrolysis of the enantiomerically enriched mixtures of thiol esters thus obtained yielded the (S)-enantiomers of ibuprofen and naproxen with ees up to 82%. (C) 2003 Elsevier Science Ltd. All rights reserved.