1: 26 percent / methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 10 h 2: sodium ethoxide / ethanol / 0.75 h View Scheme

1: 26 percent / methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 10 h 2: sodium ethoxide / ethanol / 0.75 h 3: 1.) tri-n-butylstannyl oxide / 1.) ethanol, reflux, 2 h, 2.) ether, 3 d, RT 4: methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 3 h / Ambient temperature 5: aq. sodium hydroxide / 1 h / Ambient temperature 6: 61 percent / ethanol; trifluoroacetic acid / 2.5 h / Irradiation View Scheme

1: 26 percent / methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 10 h 2: sodium ethoxide / ethanol / 0.75 h 3: 1.) tri-n-butylstannyl oxide / 1.) ethanol, reflux, 2 h, 2.) benzene, 10 h, reflux 4: methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 19 h / Ambient temperature 5: aq. sodium hydroxide / 2 h / Ambient temperature 6: 21 percent / ethanol / 3 h / Irradiation View Scheme

1: 26 percent / methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 10 h 2: sodium ethoxide / ethanol / 0.75 h 3: 1.) tri-n-butylstannyl oxide / 1.) ethanol, reflux, 2 h, 2.) ether, 140 h, RT View Scheme

1: 26 percent / methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 10 h 2: sodium ethoxide / ethanol / 0.75 h 3: 1.) tri-n-butylstannyl oxide / 1.) ethanol, reflux, 2 h, 2.) ether, 3 d, RT View Scheme

1: 26 percent / methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 10 h 2: sodium ethoxide / ethanol / 0.75 h 3: 1.) tri-n-butylstannyl oxide / 1.) ethanol, reflux, 2 h, 2.) ether, 140 h, RT 4: methyltriphenylphosphonium iodide / hexamethylphosphoric acid triamide / 24 h / Ambient temperature View Scheme