Asymmetric synthesis of meso- and (2R,4R)-2,4-diaminoglutaric acids
摘要:
In order to synthesize meso- and (2R,4R)-2,4-diaminoglutaric acids, a synthetic route has been developed starting from Garner's aldehyde and where the key steps are the asymmetric hydrogenations of (E)- and (Z)-(R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-[2'-(benzamido)-2'-(methoxycarbonyl)ethenyl]-1,3-oxazolidine, under heterogeneous conditions, followed by oxidation and further hydrolysis. A model is proposed to explain the stereochemical outcome of the asymmetric hydrogenation. (C) 1997 Elsevier Science Ltd.
Catalytic hydrogenation of methyl esters of some 1h-pyrazoline-3-carboxylic acids
作者:V. A. Gorpinchenko、D. V. Petrovcx、S. S. Lozhkin、E. G. Galkin、V. A. Dokichev
DOI:10.1007/s10593-010-0408-2
日期:2009.10
Hydrogenation over Raney nickel of the methyl ester of 1H-pyrazoline-3-carboxylic acid and also of its 4-phenyl and 5-methoxycarbonyl-substituted analogs, leads respectively to 3-aminopyrrolidin-2-one, its 4-phenyl- and 5-methoxycarbonyl derivatives, predominantly to the trans isomer. Under the same conditions 1-amino-4-methoxycarbonylpyrrolidin-2-one was obtained from 3,4-di(methoxycarbonyl)-1H-pyrazoline