1: tetrakis(triphenyl phosphite)-nickel(0)-triphenyl phosphite 2: 65 percent / aq. HCl / methanol / Heating View Scheme

in acetonitrile Irradiation (UV/VIS); mixt. of Co complex and enyne in acetonitrile, which was deaerated in ultrasonic bath with bubbling argon, was refluxed for 19 h under argon; condensed in vac.; residue was pass through column of Florisil (CH2Cl2);eluate was subjected to TLC sepn. (hexane-ethyl acetate, 10/1);

methyllithium in tetrahydrofuran 1.) -78 deg C, 10 min, -20 deg C, 1 h; 2.) r.t., 30 min;