NEW AGENTS OF BIARYL OXIDATIVE COUPLING IN FLUORO ACID MEDIUM .6. APPLICATION TO THE SYNTHESIS OF PHENOLIC BISBENZOCYCLOOCTADIENE LIGNANS

摘要

A systematic study of redox couples in fluoro acid medium has been carried out for the oxidative coupling of bisbenzocyclooctadiene lignan precursors. Tl2O3 and Re2O7 were found to be the more efficient reagents with precursors possessing methylenedioxy substituents far the former and only methoxy groups for the latter. Finally, oxidative coupling of a phenolic dibenzylbutane led to a mixture of two BBCOD's, resulting from para and ortho coupling to the phenolic group. [References: 26]