in hexane a soln. of freshly sublimed 1,4-(3,3-dimethyl-1-butynyl)benzene in n-hexane was treated with dineopentylgallium hydride, the mixt. was heated atreflux for 14 h, cooled to room temp.; concd., the solvent was removed in vac., the residue was evacuated (<1E-2 Torr) at 50°C for 3 h, recrystd. from toluene (20/-15°C); elem. anal.;

in hexane under Ar atm. soln. R2GaH in hexane was treated with soln. bisalkyne in hexane at room temp. and heated under reflux for 15-20 h; soln. was cooled to room temp. and filtered, concd. in vacuo at room temp. and cooled to -80°C, Ga(CH2-t-Bu)3 was removed at 55°C (1E-3 Torr), recrystn. from n-hexane; elem. anal.;

in hexane (Ar); treatment of acetylene deriv. with gallium compd. in hexane at reflux for 15 h; NMR;