Vulgarone B

The crystal structure of vulgarone B (2,6,6,11-tetra­methyl­tri­cyclo­[5.4.0.02,8]­undec-10-en-9-one), a carbocyclic sesquiterpene with the formula C15H22O, is reported. All intramolecular geometric parameters are as expected. The mol­ecule contains a four-membered ring, in which all atoms are stereogenic. The 1,3 and 2,4 atoms of this cyclo­butane are bridgehead C atoms which form part of six-membered and seven-membered rings.