Hypolipidemic activity of some derivatives of 6H-dibenzo[b,d]pyran

This paper describes the synthesis of 6-carboxy derivatives of 6H-dibenzo[b,d]pyran. These compounds are among the most rigid structures related to clofibrate ever synthesized, which means they have very few possible conformations of relative stability compared with the many for clofibrate. Compound 6H-2-chloro-6-methyl-dibenzo[b,d]pyran-6-carboxylic acid 3g showed very high hypolipidemic activity being 12 times more potent than clofibrate in reducing plasma cholesterol concentration in the hypercholesterolemic rat and 11 times more potent in reducing plasma triglyceride concentration in the normolipemic rat.