Synthetic studies on (+)-wortmannin. An asymmetric construction of an allylic quaternary carbon center by a Heck reaction

Abstract Treatment of (±)- 4 with Pd(OAc) 2 , DPPP, TBAB and K 2 CO 3 in toluene gave 16β in a highly stereoselective manner (17:1, 90%). Moreover, reaction of (±)- 4 with Pd(OAc) 2 , ( R )-Tol-BINAP and K 2 CO 3 in toluene afforded 16β in 96% ee and in 20% yield.