The structure and stereochemistry of two new dihydroflavonol glycosides

Lecontin and (+)-fustin glucoside, two new members of the rare group of flavonoids the dihydroflavonol 3-O-glycosides, are shown to have structures I and II, respectively. ORD, CD and NMR data are presented for these and other dihydroflavonol 3-O-glycosides and the relationship between absolute stereochemistry and the order and sign of Cotton effects in this class of glycosides is established.