[4 + 3]Cycloaddition Reactions: Synthesis of 9,10-Dimethoxy-9,10-propanoanthracen-12-ones

Abstract

Cycloaddition of 9,10-dimethoxyanthracene (1) to tetrabromoacetone (2a) under a variety of conditions afforded isomers 3a,b; reductive debromination of 3a,b afforded 4, while reduction with NaBH4 gave alcohol 6 which on reductive debromination gave olefin 7; reaction of 1 with 2b gave isomers 8a,b.