Bromination of the cation radical from a derivative of 2,3,6,7 -tetrahydrobenzo[1,2-b;4,5-b′]difuran

Abstract

Abstract As a result of the fusion with five-membered oxygen rings, 2.3.6.7-tetrahydro- 2,2,4,6,6,8-hexamethylbenzo[1,2- b ;4,5- b ′]difuran ( 2a ) readily forms a cation radical ( 3 ), characterized as the tribromide and the hexachloroantimonate, that is halogenated by bromine or N-bromsuccinimide at any of the benzylic positions but with some preference for the ring methylene groups; the halogen in the products is so labile, however, that workup affords as the main product (33%) the 3,7-dione ( 4a ).