The absolute configuration of dichapetalin A

Abstract

The absolute configuration of dichapetalin A, [(4 α,6′ α,7 α,17 α,20 S,23 R,24 E)-2′,3′,5′,6′-tetrahydro-7,23,26-trihydroxy-6′-phenyl-13,30-cyclo-29-nordammara-2,11,24-tri-eno [4,3-c]pyran-21-oic acid γ-lactone], the major cytotoxic constituent from Dichapetalum madagascariense has been established to be 4 R,5 R,7 R,8 R,9 R,10 S,13 R,14 S,17 S,20 S,23 R,6′ S.