Syntheses of lignans from 2,3-diarolybutanes

Abstract

2,3-Diarolybutanes can be selectively converted with high stereospecificity into 2,5-diaryl-3,4-dimethylfurans or 2,3-diarylbutanes. The racemic forms of the dibenzylbutane ligans, dihydroguaiaretic acid dimethyl ether (2), austrobilignan-5 (12), and austrobilignan-6 (14) and the diaryltetrahydrofuran lignans, veraguensin (3) and its piperonyl analogue (10) have been readily synthesized. A short convenient synthesis of the aryltetralin lignan, galbulin (5) and the all-trans-tetrahydrofuran lignan, galbelgin (6) are also reported.