Biphenylenes. Part XVI. Preparation and Baeyer–Villiger oxidation of some 2-acetylbiphenylenes

Abstract

Baeyer–Villiger oxidation of 2-acetylbiphenylene and its 6-benzoyl and 3-methoxy-derivatives gave the corresponding 2-acetoxy-compounds. Similar oxidation of 2,6-diacetylbiphenylene gave a mixture of 2-acetoxy-6-acetyl- and 2,6-diacetoxy-biphenylene. These compounds were converted into 2-acetyl-6-methoxy- and 2,6-dimethoxy-biphenylene, respectively, by combined hydrolysis and methylation. Oxidation of 2,7-diacetyl-biphenylene gave the 2,7-diacetoxy-compound.

Fries rearrangement of 2-acetoxybiphenylene gave the 2-acetyl-3-hydroxy-compound, which was methylated to 2-acetyl-3-methoxybiphenylene. The latter was also obtained by Friedel–Crafts acetylation of 2-methoxy-biphenylene.