copper (I) cyanide in tetrahydrofuran under Ar or N2; at -70 to -20°C, 4h; not isolated, detcted by GC analysis;

copper (I) cyanide in tetrahydrofuran under Ar or N2; the allene added to the Sn-Al compd. in THF followed by CuCN at -78°C, warmed to room temp. over 15h; hydrolyzed by addn. of MeOH, aq. NH4Cl, extn. (ether), flash chromy. (ethyl acetate : n-hexane = 1:9), elem. anal.;

in tetrahydrofuran under Ar or N2; at -78°C, 1.5h;