1,1-dimethylpropan-1-ol; sodium hydride 1.) THF, 25 deg C, 2.) benzene, DMSO, 60 deg C, 30 min; Yield given. Multistep reaction;

1: 77 percent / triphenylphosphine / 1.) dichloromethane, 5 deg C, 1 h, 2.) 20 deg C, overnight 2: 68 percent / potassium t-amylate / hexane / 1.) 0 - 20 deg C, 30 min, 2.) 20 deg C, overnight 3: 1.) butyl-lithium / 1.) THF, -78 deg C, 2 h, 2.) 48 h 4: 52.5 percent / pyridine / 48 h / 0 °C 5: 1.) potassium hydride, 2.) 18-crown-6 / 1.) THF, 0 deg C, 5 min, 2.) 1,2-dimethoxyethane, 80 deg C, overnight View Scheme

bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide in triethylamine T=65°C; Sonogashira coupling; 16 h;

tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran T=60°C;

1: With gallium(III) chloride in dichloromethane T=-78°C; chelation; 0.5 h; 2: With tri-n-butyl-tin hydride T=-78°C; Reduction; 1 h; Further stages.;