1: hex-1-yne With ethylmagnesium bromide in tetrahydrofuran; diethyl ether T=20°C; 1 h; 2: 1-(dimethyl(phenyl)silyl)propan-1-one in tetrahydrofuran; diethyl ether T=-78 - 20°C; 3 h;

n-butyllithium in tetrahydrofuran T=0°C; 1,2-Brook process;