Regioselective formation of 2-alkoxyoxetanes in the photoreaction of aromatic carbonyl compounds with β,β-dimethyl ketene silyl acetals: notable solvent and silyl group effects

Regioselective formation of 2-alkoxyoxetanes 3 was achieved in the photoreactions of aromatic ketones 2 with electron-rich ketene silyl acetals 1. In the photoreactions, the silyl-migration adduct 5 was also formed together with the oxetane 3. The product ratios of 3 and 5 were largely dependent on the solvent used and the silyl group of 1. The exclusive formation of 2-alkoxyoxetanes 3 was controlled by proper choice of the solvent and silyl group.