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;

bis(acetylacetonate)nickel(II); triphenylphosphine in tetrahydrofuran T=20°C; Inert atmosphere; regioselective reaction;