Stereoselective synthesis of both enantiomers of N-Boc-α-aryl-γ-aminobutyric acids
摘要:
Esterification of racemic alpha-aryl-beta-cyanopropionic acid chlorides with either (R)- or (S)-N-phenylpantolactam as the chiral auxiliary in the presence of Et3N resulted in the predominant formation of (alphaR,3'R)- or (alphaS,3'S)-configured pantolactam cyano ester, respectively, in nearly quantitative yields with diastereomeric ratios of up to 93:7. Column chromatography of the diastereoenriched cyano esters, followed by hydrolysis of the resulting diastereopure cyano esters under essentially nonracemizing conditions gave enantiopure alpha-aryl-beta-cyanopropionic acids, which were readily converted in high yields into enantiopure (OER)- and (alphaS)-configured N-tert-butoxycarbonyl-alpha-aryl-gamma-aminobutyric acid (GABA) derivatives of potential biological interest. (C) 2003 Elsevier Ltd. All rights reserved.
Stereoselective synthesis of both enantiomers of N-Boc-α-aryl-γ-aminobutyric acids
摘要:
Esterification of racemic alpha-aryl-beta-cyanopropionic acid chlorides with either (R)- or (S)-N-phenylpantolactam as the chiral auxiliary in the presence of Et3N resulted in the predominant formation of (alphaR,3'R)- or (alphaS,3'S)-configured pantolactam cyano ester, respectively, in nearly quantitative yields with diastereomeric ratios of up to 93:7. Column chromatography of the diastereoenriched cyano esters, followed by hydrolysis of the resulting diastereopure cyano esters under essentially nonracemizing conditions gave enantiopure alpha-aryl-beta-cyanopropionic acids, which were readily converted in high yields into enantiopure (OER)- and (alphaS)-configured N-tert-butoxycarbonyl-alpha-aryl-gamma-aminobutyric acid (GABA) derivatives of potential biological interest. (C) 2003 Elsevier Ltd. All rights reserved.
Stereoselective synthesis of both enantiomers of N-Boc-α-aryl-γ-aminobutyric acids
作者:Pelayo Camps、Diego Muñoz-Torrero、Laura Sánchez
DOI:10.1016/j.tetasy.2003.10.035
日期:2004.1
Esterification of racemic alpha-aryl-beta-cyanopropionic acid chlorides with either (R)- or (S)-N-phenylpantolactam as the chiral auxiliary in the presence of Et3N resulted in the predominant formation of (alphaR,3'R)- or (alphaS,3'S)-configured pantolactam cyano ester, respectively, in nearly quantitative yields with diastereomeric ratios of up to 93:7. Column chromatography of the diastereoenriched cyano esters, followed by hydrolysis of the resulting diastereopure cyano esters under essentially nonracemizing conditions gave enantiopure alpha-aryl-beta-cyanopropionic acids, which were readily converted in high yields into enantiopure (OER)- and (alphaS)-configured N-tert-butoxycarbonyl-alpha-aryl-gamma-aminobutyric acid (GABA) derivatives of potential biological interest. (C) 2003 Elsevier Ltd. All rights reserved.