Optical And Photochemical Properties Of Methylisopulegone

UV irradiation of ( −)methylisopulegone (II), the configurationi of which is established by comparison of its CD with that of 2-isopropenyl-2-methylcyclohexanone made from (+)camphor, gives in high yield 3,6-dimethyl-7-methylenebicyclo[4,2,0]octan-1-ol (XVIII), which is further isomerized by acid to (−)3,4,7-trimethylcyclo-oct-3-enone (XIX).