1: 93 percent / (NH4)2SO4 / toluene / Heating 2: 1.) t-BuLi; 2.) pentynylcopper / 1.) 80percent ether/THF, -20 deg C, 1 h; 2.) THF, -20 deg C, 0.5 h, -> -78 deg C; 3.) -20 deg C View Scheme

1-pentynyl-copper; tert.-butyl lithium 1.) 80percent ether/THF, -20 deg C, 1 h; 2.) THF, -20 deg C, 0.5 h, -> -78 deg C; 3.) -20 deg C; Yield given. Multistep reaction;

n-butyllithium; 5-hexenyl bromide 1.) THF-ether, -20 deg C, 1 h; 2.) THF-ether, -78 deg C; Yield given. Multistep reaction;

tert.-butyl lithium 1.) THF-ether, -20 deg C, 1 h; 2.) THF-ether, -78 deg C; Yield given. Multistep reaction;