Regioselective synthesis of 1- and 4-tetralones from heteroaryl-3-cyclobutanols

Herein we describe the first transition-metal-free ring expansion of four-membered rings to 1-tetralones from 3-substituted heteroaromatic compounds, and the first example of an oxetanol ring expansion to an oxa-tetralone. We also experimentally investigate the mechanism of the silver-mediated ring expansion and elucidate the active oxidant in these systems using electrochemical techniques. (C) 2020 Elsevier Ltd. All rights reserved.