First enantioselective synthesis of (−)- and (+)-virgatusin, tetra-substituted tetrahydrofuran lignan

Abstract

The first highly enantioselective syntheses of tetra-substituted tetrahydrofuran lignan, (−)- and (+)-virgatusin, were achieved. Hemiacetal 15 was stereoselectively obtained from Evans's syn-aldol product 8 as a single isomer. This hemiacetal 15 was converted to (−)-virgatusin via hydrogenolysis. (+)-Virgatusin was also synthesized through the same process. The enantiomeric excess of the both enantiomers was determined as more than 99% ee.