Synthesis of the Pentasubstituted Lichen p-Terphenyls Butlerins A, B and C

Abstract

Total syntheses of the p-terphenyls butlerin A (1) (3′,4,4′′,6′-tetramethoxy[1,1′:4′,1′′-terphenyl]-2′-yl acetate), butlerin B (2) (3′,4,4′′,5′-tetramethoxy[1,1′:4′,1′′-terphenyl]-2′-yl acetate) and butlerin C (3) (3′,4,4′′-trimethoxy[1,1′:4′,1′′-terphenyl]-2′,6′-diyl diacetate), previously isolated from the lichen Relicina connivens, are reported.