Study of the inf luence of the alkyl ester group in (S)-valinates on diastereoselectivity of their condensation with N-acetylphenylalanine by the mixed anhydride method
作者:E. A. Zhdanova、N. Z. Solieva、L. Sh. Sadretdinova、M. A. Ezhikova、M. I. Kodess、V. P. Krasnov
DOI:10.1007/s11172-006-0353-5
日期:2006.5
The dynamic kinetic resolution in the synthesis of alkyl N-acetylphenylalanyl (S)-valinates was studied by the mixed anhydride method. The structure of the ester group of the amino component appeared to exert no substantial effect on the diastereoselectivity of the reaction.
Novel synthetic routes to N-(2-amino-9H-purin-6-yl)-substituted amino acids
作者:Alexey Yu. Vigorov、Viktor P. Krasnov、Dmitry A. Gruzdev、Alisa A. Men'shikova、Alexander M. Demin、Galina L. Levit、Valery N. Charushin
DOI:10.1016/j.mencom.2013.12.011
日期:2014.1
Reaction of N-2-protected 2-amino-6-chloropurine with tert-butyl (S)-phenylalaninate, (R)- and (S)-valinates followed by deprotection affords 2-aminopurines bearing at 6-position the corresponding amino acid moieties, whose chiral centre is partially racemized.
Efficient large (ca. 40 g) laboratory scale preparation of (S)- and (R)-valine tert-butyl esters
作者:Victor P. Krasnov、Galina L. Levit、Iraida M. Bukrina、Alexander M. Demin、Oleg N. Chupakhin、Ji Uk Yoo
DOI:10.1016/s0957-4166(02)00532-3
日期:2002.9
A large laboratoryscale (ca. 40 g) method for the preparation of enantiomerically pure (S)- and (R)-valine tert-butyl esters has been developed. The method involves three steps: preparation of N-TFA-valines, preparation of valine tert-butyl esters using 2-methylpropene in dioxane in the presence of sulfuric acid, and isolation of the target compounds as the acetate derivative. The overall yield is