Diastereoselective synthesis of β- and γ2-muurolene. A carbocationic pathway from mono- to sesquiterpenes
The Lewis acid catalysed addition of the piperityl chlorides 6 to isoprene yields adduct 7, which undergoes a cis-stereoselective cyclisation to give the diastereoisomeric muurolene monohydrochlorides 8. Treatment with potassium tert-butoxide affords β- and γ2- muurolene 2.