The rearrangement of 11,13-dibromo-9,10-dimethoxy-9,10-propanoanthracen-12-ones to the corresponding Favorskii products

摘要

Submitting cis- and trans-11,13-dibromo-9,10-dimethoxy-9,10-propanoanthracen-12-one (4a,b) to Favorskii conditions (MeOH/KOH, 60 degrees C) afforded the Favorskii ester 5a and the alpha-keto acetal 5b in 46% overall yield. Almost all reactions resulted in the formation of a single isomer which could be shown to be the most favored one by molecular mechanics calculations (MM2).