A New Conversion Method from (-)-Limonene to Nepetalactones

抄録

This paper describes the conversions of (-)-limonene to four nepetalactones (1, 2, ent-3 and 4) in a stereocontrolled manner. The cis-3, 4-disubstituted cyclopentanone (5) obtained from (-)-limonene via Rh(I)-catalyzed cyclization of the 4-pentenal, could be converted to the bicyclo[3.3.0]octenone (6). After the stereoselective conversion of 6 into the diastereomeric isomers of the ketones (8 and 16), a sequence of reactions involving the silyl enol ethers (18 and 19), ozonolysis, and subsequent lactonization afforded the target molecules.