1: With Et3NBnCl; sodium hydroxide in dichloromethane; water T=0 - 20°C; Doering-LaFlamme allene synthesis; Inert atmosphere; 2: With ethyl magnesium chloride in tetrahydrofuran T=0°C; Doering-LaFlamme allene synthesis; 2 h; Inert atmosphere;

tetrakis(triphenylphosphine) palladium(0); tetrabutyl ammonium fluoride 1) THF, 2) dioxane, 35 deg C, 3 h; Yield given. Multistep reaction;