Synthesis of 1-aryl-2,3-diaroyl cyclopropanes from 1,3,5-triaryl-1,5-diketones and their transformation into E, E-1,4-diaryl-1,3-butadienes†

Abstract

A new method for the synthesis of 1-aryl-2,3-diaroyl cyclopropanes has been developed by iodine/DBU-mediated cyclization of 1,3,5-triaryl-1,5-diketones. The alcohols derived by the reduction of these cyclopropanes, when treated with conc. HCl, afforded a series of 1,3-dienes through cyclopropyl ring-opening and subsequent fragmentation. Overall, the synthetic sequence represents a new non-Wittig methodology for the synthesis of 1,3-dienes from 1,5-diketones.

Abstract

1-Aryl-2,3-diaroyl cyclopropanes, synthesized by iodine/DBU-mediated cyclization of 1,3,5-triaryl-1,5-diketones, when subjected to reduction followed by treatment with conc. HCl afforded E, E-1,5-diaryl-1,3-butadienes.