5-tert-Butylproline

E Beausoleil, B L'Archevêque, L Bélec…

Index: Beausoleil; L'Archeveque; Belec; Atfani; Lubell Journal of Organic Chemistry, 1996 , vol. 61, # 26 p. 9447 - 9454

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Citation Number: 61

Abstract

Steric effects on the isomer equilibrium of amides N-terminal to proline can be explored with 5-alkylprolines having bulky 5-position substituents. Enantiopure 5-tert-butylprolines were thus synthesized from glutamic acid via an acylation/diastereoselective reductive amination sequence. Double deprotonation of γ-methyl N-(PhF) glutamate (2) with LiN (SiMe3) 2 and C-acylation with pivaloyl chloride provided β-keto ester 3, which upon γ-ester hydrolysis ...