Reactions of 3-triphenylphosphoranylidene-[b]fused furan-2(3H)-ones with some salicylaldehydes: new synthesis of 3-(2-hydroxyaryl)-coumarins and coumestans

Abstract

Reactions of the ylide 1 and o-hydroxybenzaldehydes 2a–c gave, depending on the reaction conditions, 3-(2-hydroxyphenyl)coumarin derivatives 5a–c, 3-(2-hydroxybenzylidene)benzo[b]furan-2(3H)-one 4 and, in one step, the coumestan derivative 6. Reaction of the ylide 11 with 2a resulted in the coumarin derivative 13 and the coumestan derivative 14.