Synthesis of the (Z) and (E) isomers of 1, 2??diaryl??3??methyl??4, 5??dioxo??3??pyrrolidinecarboxylic acid esters. Structural assignment by nmr and mass spectroscopy

…, DW Emerson, RM González

Index: Titus, Richard L.; Emerson, David W.; Gonzales, Rowena M. Journal of Heterocyclic Chemistry, 1990 , vol. 27, # 7 p. 1857 - 1860

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Citation Number: 2

Abstract

Abstract Reaction of N-benzylideneaniline, 1a, with 3-methyl-2-oxobutanedioic acid diethyl ester, 2a, produced isomeric 3-methyl-4, 5-dioxo-1, 2-diphenyl-3-pyrrolidinecarboxylic acid ethyl esters, 3a and 3b. The higher melting isomer, 3a, was shown to have the (Z) configuration by nmr spectroscopy. The (Z) and (E) isomers of 3-methyl-4, 5-dioxo-1, 2- diphenyl-3-pyrrolidinecarboxylic acid methyl esters, 3c and 3d, were prepared from 1a ...