Agarsenone, a Cadinane Sesquiterpenoid from <i>Commiphora erythraea</i>

Agarsenone (<b>1</b>), a new cadinane sesquiterpenoid, was isolated from the resin of <i>Commiphora erythraea.</i> The structures of <b>1</b> and its decomposition products agarsenolides (<b>2a</b> and <b>2b</b>) and myrrhone (<b>3</b>) were established by extensive NMR spectroscopic analysis. The absolute configuration of <b>3</b> and the relative and absolute configurations of <b>1</b> were assigned by comparison of experimental and calculated optical rotatory dispersion and electronic circular dichroism spectra