Synthesis of both enantiomers of baclofen using (R)-and (S)-N-phenylpantolactam as chiral auxiliaries

P Camps, D Muñoz-Torrero, L Sánchez

Index: Camps, Pelayo; Munoz-Torrero, Diego; Sanchez, Laura Tetrahedron Asymmetry, 2004 , vol. 15, # 13 p. 2039 - 2044

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Citation Number: 46

Abstract

Esterification of racemic 4-nitro-3-(4-chlorophenyl) butanoic acid with (R)-or (S)-N- phenylpantolactam as the chiral auxiliary allowed us to obtain the (3R, 3′ R)-or (3S, 3′ S)- nitro esters with> 98: 2 dr after column chromatography. Hydrolysis of the resulting diastereopure nitro esters gave the corresponding enantiopure nitro acids, which were readily converted in high yields into either (R)-or (S)-baclofen hydrochloride.