1: 1.) 0.25 M lithium 2-thienylcyanocuprate, 2-bromo-5-tert-butyldiphenylsilyloxy-1-pentene / 1.) THF, -78 deg C, 2 h; -78 deg C, 1 h, 2.) THF, -78 deg C, 2 h 2: 89 percent / Ti(OEt)4 / 96 h / Heating View Scheme