“…Tetraalkynylsilanes,and 1, Following the protocol for the synthesis of siloles (Scheme 4), treatment of tetraalkynylsilanes with triethylborane in boiling toluene for prolonged periods of time gives 1,1'-spirobisiloles, which can be readily protodeborylated, using acetic acid (Scheme 7). As shown above for the tetra-1-propynylsilane, the diene systems of the protodeborylated derivatives act as ligands towards Fe(CO) 3 fragments, leading to a mixture of crystalline diastereomers, one of which could be purified and studied by X-ray crystallography (Köster et al, 1993b).…”