Reaction pathways towards 1,1,2,2-tetra^tbutyldistannanes

1,2-Dichlorotetra^tbutyldistannane (1) is synthesized as a byproduct in the reaction of ^tbutylmagnesium chloride with tin tetrachloride or by the reaction of di^tbutyltindihydride with di^tbutyltin dichloride in the presence of amines. Reaction of 1 with lithium aluminumhydride yielded the dihydrido derivative 2. The treatment of 2 with bromoform gave the dibromo distannane 3 nearly quantitatively. Reactions of 2 with one equivalent of LDA or KH yielded unsymmetrically substituted alkali metal distannanes of the type M^tBu₂Sn-Sn(H)^tBu₂ (4, M = Li; 5, M = K). Reaction of either two equivalents of KH with 2, or one equivalent of KH with 5 gave the dipotassium distannide 6. The molecular structure of the dichloro derivative 1 was determined by X-ray diffraction.