Rearrangement of dypnones to 1,3,5-triarylbenzenes

Org Lett. 2015 Mar 20;17(6):1473-6. doi: 10.1021/acs.orglett.5b00353. Epub 2015 Mar 5.

Abstract

Rearrangement of dypnones to 1,3,5-triarylbenzenes is described. The reaction is proposed to involve an aldol-type self-condensation of dypnones, followed by an intramolecular [2 + 2] cycloaddition and a retro-[2 + 2] cycloaddition. The reaction goes smoothly under obviously milder conditions in comparison to the cyclotrimerization of acetophenones to 1,3,5-triarylbenzenes (10 mol % of TsOH, 80 °C versus 130-148 °C). This unexpected rearrangement would provide new possible considerations in dypnone-involved organic synthesis.