Novel generation of 9H-furo[3,2-b]chromen-9-ones from (E)-3-hydroxy-2-styrylchromones by excited state intramolecular proton transfer

Photocyclisation of substituted (E)-3-hydroxy-2-(1'-methyl-2'-phenylvinyl)-4-oxo-4H-1-benzopyrans to yield linear novel tricyclic 9H-furo[3,2-b]chromen-9-ones and angular fused tetracyclic xanthenones is described. (C) 2008 Ramesh C. Kamboj. Published by Elsevier B. V. on behalf of Chinese Chemical Society. All rights reserved.