Friedel–Crafts acylation of fluorenes; substituent effects on diacetylation
Abstract
Several mono-substituted fluorenes have been diacetylated under Friedel–Crafts conditions, and the nature and position of some substituents were shown to have a profound influence on the resulting substitution pattern. Unambiguous structural assignment was facilitated by n.m.r. Spectroscopy using lanthanide shift reagents.