Constituents of Bosistoa euodiformis (Rutaceae). Structure and synthesis of bosistoin, a triterpene with a C₃₃ skeleton

Abstract

From the wood of Bosistoa euodiformis F. Muell. only 8-sitosterol could be isolated. The bark yielded the same substance together with limonin and a small amount of skimmianine. The leaves gave substances: limonin, friedelin, epifriedelanol, franklinone, two new related substances,(S)- franklinol and franklinene, and also the new triterpene bosistoin, C₃₄H₅₈O. By degradation and synthesis from lanosterol, bosistoin was shown to be 25-ethyl-24-methylenelanost-9(11)-en-3β-yl methyl ether.