tris(dibenzylideneacetone)dipalladium(0) chloroform complex; sodium t-butanolate; (Me)CgPPh in toluene T=40°C; 20 h; Inert atmosphere;

in tetrahydrofuran; diethyl ether 1.) 0 deg C, 1 h, 2.) room temperature, 1 h;

1: 98 percent / LDA / tetrahydrofuran / 1.) -78 deg C, 1 h, 2.) room temperature, 4 h 2: 1.) oxalyl chloride, 2.) pyridine / 1.) benzene, room temperature, 17 h, 2.) CH2Cl2, room temperature, 2 h 3: 93 percent / tetrahydrofuran; diethyl ether / 1.) 0 deg C, 1 h, 2.) room temperature, 1 h View Scheme

1: 1.) oxalyl chloride, 2.) pyridine / 1.) benzene, room temperature, 17 h, 2.) CH2Cl2, room temperature, 2 h 2: 93 percent / tetrahydrofuran; diethyl ether / 1.) 0 deg C, 1 h, 2.) room temperature, 1 h View Scheme