Constituents of Eupomatia species. The structure and synthesis of eupomatene, a lignan of novel type from Eupomatia laurina R. Br

Abstract

The bark of Eupomatia laurina R. Br. yielded the known alkaloid, liriodenine, and four new substances. One of these, eupomatene, was shown by degradation to be 7-methoxy-3-methyl-2-(3?,4?- methylenedioxyphenyl)-5-trans-propenylbenzofuran. The dihydro derivative and eupomatene itself were synthesized. It is proposed that the term ?lignan? be extended to cover all natural products of low molecular weight that arise primarily from the oxidative coupling of p- hydroxyphenylpropene units and that eupomatene be then classified as a lignan.     A chlorotropolone has been isolated from a Reimer-Tiemann reaction on a simple phenol.