The reaction of tryptophan and derivatives with some 1,3-dicarbonyl compounds

Abstract

Enamine methyl esters are obtained by methylation of the condensation product from a 1,3-dicarbonyl compound with L-tryptophan, or directly from methyl L-tryptophanate and the 1,3-dicarbonyl compound. Protonation of these enamines forms either methyl L-tryptophanate or a tetrahydro-β-carboline derivative (two diastereomers in certain cases), depending on the structure of the dicarbonyl compound. Enamines from 1,3-dicarbonyl compounds and tryptamine yield similar cyclic products on protonation.