Synthesis of potential metabolites of ethyl (E)‐4‐[2‐(3,4‐dihydro‐4,4‐dimethyl‐2H‐1‐benzopyran‐6‐yl)‐1‐propenyl]benzoate

Abstract

Potential metabolites of ethyl (E)‐4‐[2‐(3,4‐dihydro‐4,4‐dimethyl‐2H‐1‐benzopyran‐6‐yl)‐1‐propenyl]benzoate were synthesized. The new compounds include ethyl 3‐[3,4‐dihydro‐4,4‐dimethyl‐2H‐1‐benzopyran‐6‐yl]crotonate, 3‐[3,4‐dihydro‐4,4‐dimethyl‐2H‐1‐benzopyran‐6‐yl]crotonic acid, 3,4‐dihydro‐4,4‐dimethyl‐2H‐1‐benzopyran‐6‐carboxylic acid, 4‐[3,4‐dihydro‐4,4‐dimethyl‐2H‐1‐benzopyran‐6‐yl]Δ2‐butenolide, ethyl (E)‐4‐[3,4‐dihydro‐4,4‐dimethyl‐2W‐1‐benzopyran‐6‐yl)‐3‐hydroxy‐1‐ propenyl]benzoate, ethyl (E)‐4‐[2‐(3,4‐dihydro‐4,4‐dimethyl‐2H‐1‐benzopyran‐6‐yl)‐2‐propenal]benzoate, and ethyl (E)‐4‐[2‐(3,4‐dihydro‐4,4‐dimethyl‐2H‐1 ‐benzopyran‐6‐yl)‐2‐propenoic] acidjbenzoate. Stereospecific oxidizing reagents and/or conditions were developed for these sensitive systems and include the use of SeO2, Clorox bleach, activated MnO2, and NaCIO2 in the presence of resorcinol as a chlorine scavenger. Copyright © 1993 Wiley‐Liss, Inc., A Wiley Company