1: 1.) (c-C6H11)2BH, 2.) aq. NaOH / 2.) Pd(PPh3)4 / 1.) THF, r.t., 1 h, 2.) benzene, 65 deg C, 1 h 2: 70percent m-CPBA / CH2Cl2 / 1 h / Ambient temperature 3: BF3*Et2O, MeOH / 0.5 h / 0 °C 4: 1.) t-BuLi, 2-thienyl(cyano)copper lithium / 1.) pentane, Et2O, -78 deg C, 30 min; THF, -78 deg C, 30 min, 2.) -78 deg C, 1 h 5: 93 percent / HF*pyridine, pyridine / acetonitrile / 4 h / Ambient temperature View Scheme

tert.-butylhydroperoxide; cis-(2,2)-Rh2(cap)4 in water T=40°C; 30 h;