in not given ratio of educts 1:1;

copper (I) cyanide in not given to soln. of alkyne added (n-Bu)3SnAlEt2 and 5 molpercent catalyst, then treated with H3O(1+) at 0 °C for 10 min; ratio of C10H21C(SnBu3)CH2 : (C10H21)CHCH(SnBu3) 62:38; combined yield - 87percent;

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.;