acetyl chloride in tetrahydrofuran (Ar); addn. of CuCN to a soln. of the stannyllithium in THF at -78°C, dropwise addn. of the allene to this soln., stirring, addn. of CH3COCl at -100°C, soln. is kept at -100°C for 1,5 h; quenching with methanol at -100°C, elem. anal.;

acetyl chloride React. of starting materials at -78°C, and then quenching with AcCl (-78 to 0°C).;

acetyl chloride React. of starting materials at -100°C.; Quenching of intermediate with MeOH at -100°C.;