Asymmetric reactions of α-ketoacid-derived hemiacetals: Stereoselective synthesis of α-hydroxy acids
摘要:
N-Acylation of prolinol with alpha-ketoacid chlorides results in concomitant hemiacetalization of the alpha-keto amide by the prolinol hydroxyl group, (R) or (S) alpha-hydroxy acids are obtained with good enantiomeric excess by stereodivergent reduction of these hemiacetals. Reaction with Grignard reagents at ambient temperature furnishes (R) alpha-alkyl mandelic acids with good stereoselectivity. (C) 1998 Elsevier Science Ltd. All rights reserved.
Asymmetric reactions of α-ketoacid-derived hemiacetals: Stereoselective synthesis of α-hydroxy acids
摘要:
N-Acylation of prolinol with alpha-ketoacid chlorides results in concomitant hemiacetalization of the alpha-keto amide by the prolinol hydroxyl group, (R) or (S) alpha-hydroxy acids are obtained with good enantiomeric excess by stereodivergent reduction of these hemiacetals. Reaction with Grignard reagents at ambient temperature furnishes (R) alpha-alkyl mandelic acids with good stereoselectivity. (C) 1998 Elsevier Science Ltd. All rights reserved.