Studies in the synthesis of furocoumarins. XIV. Synthesis of psoralene from 2-bromoresorcinol

Abstract

A synthesis of psoralene and alkylpsoralenes from 2-bromoresorcinol is described. Treatment of 2-iodomethyl-8-oxo-2,3-dihydro-8H-furo[2,3.h][l]benzopyran with sodium and ethanol is shown to yield 2-methyl-8-oxo-8H-furo[2,3-h][1]- benzopyran rather than the corresponding dihydrofuran.