Oligomeric flavanoids. Part 26. Structure and synthesis of the first profisetinidins with epifisetinidol constituent units

Abstract

The natural occurrence of the first oligomeric profisetinidins with (2R,3R}-2,3-cis-epifisetinidol chain extender units is demonstrated in the bark of Pithecellobium dulce (Guamuchil). Semi-synthesis using the appropriate flavan-3-ol and flavan-3,4-diol precursors permits unequivocal structural and stereochemical assignment of the novel dimeric epifisetinidol-(4β,8)-catechin and epicatechins 16 and 18, the trimeric bisepifisetinidol-(4β,6:4β,8)-catechin and epicatechins 33 and 35, the fisetinidol-(4α,8)-catechin-(6,4β)-epifisetinidol 37 and fisetinidol-(4α,8}-epicatechin-(6,4β}-epifisetinidol 39.

Citation

Steynberg, Petrus J.; Steynberg, Jan P.; Brandt, E. Vincent; Ferreira, Daneel; Hemingway, Richard W. 1997. Oligomeric flavanoids. Part 26. Structure and synthesis of the first profisetinidins with epifisetinidol constituent units. Journal of the Chemical Society, Perkin Trans. 1:1943-1950