Tetranortriterpenoids and related substances. Part XIII. The constitution of grandifoliolenone, an apo-tirucallol derivative from Khaya grandifoliola(meliaceae)

Abstract

Grandifoliolenone from Khaya grandifoliola is formulated as structure (3) on the basis of chemical and spectroscopic evidence. The isolation of the corresponding 16-ketone from the same plant is reported. These are the first examples of naturally occurring apo-tirucallol derivatives and their isolation provides strong support for the current proposals for the biogenesis of tetranortriterpenoids.