Reactions of substituted hydroxybenzofurans. III. Acylation of 5- and 6-Methoxy-2,3-diphenylbenzofurans

Abstract

Vilsmeier-Haack formylation of 5-methoxy-2,3-diphenylbenzofuran (1a) and 6-methoxy-2,3-diphenylbenzofuran(2a) gave the corresponding 6- formyl derivative (1b) and 5-formyl derivative (2b) respectively. Friedel-Crafts acetylation of (1a) and (2a) gave products of the same orientation. The aldehydes (1b), (2b) were converted by standard methods into the corresponding methyl ketones and substituted 2,3- diphenyl-6H-furo[2,3-g][1]benzopyran-6-ones and 2,3-diphenyl-7H- furo[3,2-g][1]-benzopyran-7-ones respectively.