Asymmetric Heck Reaction−Carbanion Capture Process. Catalytic Asymmetric Total Synthesis of (−)-Δ⁹⁽¹²⁾-Capnellene

Abstract

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 (−)-Δ 9(12) -capnellene ( 7 ) was achieved for the first time, using 6b as a key intermediate and a radical cyclization as a key step.