Oxidative β-Cleavage of Fused Cyclobutanols Leading to Hydrofuran-Fused Polycyclic Aromatic Compounds

Abstract

Treatment of aryl-fused bicyclo[4.2.0]­octanols with an oxidant such as phenyliodine diacetate (PIDA) or hypochlorous acid gave dihydrofuran-containing polycyclic aromatic compounds by selective β-cleavage of the cyclobutanol moiety. Mechanistic studies suggest that the oxygen atom of the hydrofuran ring is incorporated from the hydroxy group of the substrate via intramolecular addition. The oxidative transformation should serve as a new method to prepare functionalized polycyclic aromatic compounds.

Total Synthesis of Atrachinenins A and B

“…Under basic conditions, the vinylogous α-ketol rearrangement was combined with the aerobic oxidation step to directly convert 14 to 17 in high yield. Finally, oxidation of 14 with PhI­(OAc) 2 gave an interconverting mixture of the atrachinenin C analogue 20 alongside its ring closed cyclic hemiacetal 21 (1.3:1 in CDCl 3 ) via C–C cleavage of the alkoxy radical 19 . X-ray analysis of crystals of 21 proved its cyclic structure, which reverted back to a mixture of 20 and 21 on dissolution in CDCl 3 .…”