Reaction of N-trimethylsilyl benzil monoimine with simple lithium ester enolates. A synthetic tool for the regioselective one-pot preparation of novel polyfunctional pyrrolines

Abstract

Sequential treatment of benzil with lithium hexarnethyldisilylamide and simple α-lithiated esters leads, in a regioselective one-pot process, to the polyfunctional pyrrolines(4)–(8), depending on the nature of the enolate and on the experimental conditions. A reasonable explanation for the observed results is discussed. In addition, the reaction of 2,5-dihydro-5-hydroxy-4,5-diphenyl-2-oxo-1H-pyrrole-3-carbonitrile with sodium hydroxide has been reinvestigated and the structure of the previously described product corrected.