PREPARATION AND SOME SUBSEQUENT TRANSFORMATIONS OF TETRAETHYNYLMETHANE

Tetraethynylmethane (1) was synthesized in 10 steps and 33% overall yi eld from bis[(trimethysilyl)ethynyl] ketone. This route features (1) c onstruction of the critical central quaternary center via the agency o f a [3,3] sigmatropic shift and (2) installation of the fourth acetyle ne unit in a very sterically demanding environment. Alternative routes and model systems which were more informative than productive are als o discussed. Finally, transition metal-mediated coupling of the rather unstable 1 (and derivatives) with unsaturated partners furnished a va riety of relatively stable polylalkynylated species which could be man ipulated without event.