Lirioresinol-C dimethyl ether, a diaxially substituted 3,7-dioxabicyclo[3,3,0]octane lignan from Macropiper excelsum(Forst.f.) Miq.

Abstract
Lirioresinol-C dimethyl ether, a lignan from the wood of Macropiper excelsum, has been shown to be a diaxially substituted 3,7-dioxabicyclo[3,3,0]octane (Ia). The stereochemistry of lirioresinol-A and lirioresinol-B, isomers from the hydrolysis of a lignan glucoside occurring in the bark of Liriodendron tulipifera, has been established by the use of n.m.r. spectroscopy. A second lignan from Macropiper excelsum has been shown to be identical with lirioresinol-B dimethyl ether (IIIa).