Synthesis of Racemic β-Chamigrene, a Spiro[5.5]undecane Sequiterpene
Journal article, Peer reviewed
MetadataShow full item record
Original versionMolecules 2014, 19:20664-20670 10.3390/molecules191220664
The present paper describes a total synthesis of racemic β-chamigrene (1), a sesquiterpene with a spiro[5.5]undecane carbon framework. Compared with previously reported β-chamigrene syntheses, we were able to reduce the total number of reaction steps, which also resulted in a significant improvement of the overall yield. The commercially available ketone 6-methylhept-5-en-2-one was transformed by known simple procedures into 3,3-dimethyl-2-methylenecyclohexanone. This reacted with isoprene by a Diels-Alder reaction to give a spiro ketone. An olefination reaction on this compound gave the target molecule.