| Summary: | In this paper, we describe the solvent-free three-component synthesis of 2,4,5-trisubstituted-1<i>H</i>-pyrrol-3-ol-type compounds from <i>L</i>-tryptophan. The first step of the synthetic methodology involved the esterification of <i>L</i>-tryptophan in excellent yields (93–98%). Equimolar mixtures of alkyl 2-aminoesters, 1,3-dicarbonyl compounds, and potassium hydroxide (0.1 eq.) were heated under solvent-free conditions. The title compounds were obtained in moderate to good yields (45%–81%). Density functional theory using “Becke, 3-parameter, Lee–Yang–Parr” correlational functional (DFT-B3LYP) calculations were performed to understand the molecular stability of the synthesized compounds and the tautomeric equilibrium from 3<i>H</i>-pyrrol-3-one type intermediates to 1<i>H</i>-pyrrol-3-ol type aromatized rings.
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