Efficient photochemical oxetane formation from 2-pyrones and benxophenones in the solid state

摘要

Solid-state photocycloaddition reactions of 2-pyrones (1,4) with benzophenone derivatives (2a-c,f) afforded highly site- and regioselective oxetanes (3a,3b,3c,3f,5a,5b,5c,5f) across the C5-C6 double bond in 1 or 4 via the triplet excited state of 2.The site- and regioselectivities were explained by MO calculations.