Journal of the American Chemical Society, Vol.118, No.30, 7108-7116, 1996
Asymmetric Heck Reaction-Carbanion Capture Process - Catalytic Asymmetric Total Synthesis of (-)-Delta(9(12))-Capnellene
An asymmetric Heck reaction-carbanion capture process was realized for the first time, making possible the catalytic asymmetric synthesis of various functionalized bicyclo[3.3.0]octane derivatives 6 in up to 94% ee. Sodium bromide had interesting effects on this asymmetric Heck reaction-carbanion capture process, and these effects were useful for improving the enantiomeric excess. Furthermore, the catalytic asymmetric synthesis of (-)-Delta(9(12))-capnellene (7) was achieved for the first time, using 6b as a key intermediate and a radical cyclization as a key step.
Keywords:STEREOCONTROLLED TOTAL SYNTHESIS;REGIOSELECTIVE OLEFIN INSERTION;QUATERNARY CARBON CENTERS;CIS-DECALIN DERIVATIVES;KEY INTERMEDIATE;VERSATILE INTERMEDIATE;EFFICIENT SYNTHESIS;DITERPENE SYNTHESES;ALLYLIC ALKYLATION;CARBOXYLIC-ACIDS