1: 99.9 percent / NaI / acetone / 0.08 h / with longer reaction time the cis-isomer began to isomerized to trans-isomer 2: 1.) n-BuLi; 2.) CuI-Bu3P, and Bu3P / 1.) THF, -78 deg C, 20 min, 30 min; 2.) THF, ether, -78 deg C 10 min, - 30 deg C 1 h; 3.) THF, ether, HMPA, -30 deg C, 3 h 3: 78 percent / pyridine, 50percent aq. HF / 1.) 0 deg C, 30 min; 2.) rt, 4.5 h 4: aluminum amalgam / tetrahydrofuran; H2O / addition in equal portion after 10 h, 17 h and 23h; rt 15 h View Scheme

Yield given. Multistep reaction. Yields of byproduct given;

Yield given. Multistep reaction. Yields of byproduct given;

1: NaI / acetone View Scheme

1.1: 5.1 g / sodium hydride 2.1: sodium hydride / tetrahydrofuran / 2 h / -5 °C 2.2: 74 percent / tetrahydrofuran; various solvent(s) / -78 - -25 °C View Scheme

1: NaI / acetone View Scheme

sodium iodide in acetone 0.0833333 h; with longer reaction time the cis-isomer began to isomerized to trans-isomer;

1: NaI / acetone View Scheme

carbon tetrabromide; triphenylphosphine in dichloromethane 0.666667 h;

triphenylphosphine in methanol; hexane; dichloromethane