Synthesis of chiral dihydrofuran compounds by thiourea derivatives-catalyzed “interrupted” Feist-Bénary reaction

In this study, six thiourea derivatives of cinchona alkaloids with 9-nat or 9-epi-configuration were synthesized. After characterized the structures, we adopted them to the asymmetric “interrupted” Feist-Bénary (IFB) reaction of α-haloketones with β-dicarbonyl compounds, to give optically active dihydrofurans. Various thiourea derivatives as organocatalysts were examined. The corresponding chiral hydroxyl dihydrofurans have been obtained in excellent yields and moderate ees. To the acyclic substrate, we obtained exciting and promising result.