(+/-)-(Z)-9-(Bromomethylene)-1,5,5-trimethylspirol[5.5]undeca-1,7-dien-3-one (1), a chamigrane sesquiterpene having a novel bromomethylene group is synthesized from anisole via spiroannelation of 4-(1,1-dimethyl-4-formylbutyl)-3-cyclohexen-1-one (10).
The first totalsynthesis of (±)-(Z)-9-(bromomethylene)-1,5,5-trimethylspiro[5.5]undeca-1,7-dien-3-one, a chamigrane sesquiterpene having a novel bromomethylene group is described.