Photochemical cyclization with release of carboxylic acids and phenol from pyrrolidino-substituted 1,4-benzoquinones using visible light

[GRAPHICS] Visible light irradiation of 5-acyloxymethyl- and 5-phenoxymethyl-2-pyrrolidino-1,4-benzoquinones effects photoisomerization to labile oxazolidines, which undergo elimination of carboxylate or phenolate leaving groups in high yields to generate trappable o-quinone methide intermediates.