Organostannoxane cages and aggregates of well-defined composition and structure can be prepared by the reactions of organotin oxides or organotin oxide-hydroxides with protic acids. The utility of this strategy for the preparation of dendrimer-like molecules containing a stannoxane core and a functional periphery is described.

The reaction of SnBr₄ with in situ generated 2,4,6-trimethylphenylmagnesium bromide afforded a mixture of (2,4,6-Me₃C₆H₂)₂SnBr₂ (1) and (2,4,6-Me₃C₆H₂)₃SnBr (2) which could be separated from each other by their solubility differences in diethyl ether. On the other hand, the reaction of tin metal with 2,4,6-Me₃C₆H₂CH₂Br afforded (2,4,6-Me₃C₆H₂CH₂)₂SnBr₂ (3). Hydrolysis of the latter using triethylamine as the base afforded [{(2,4,6-Me₃C₆H₂CH₂)₂Sn}₂(𝜇-O)(Br)(𝜇-OH)]₂.2CH₂Cl₂ (4) while the use of NaOH as the base afforded [{(2,4,6-Me₃C₆H₂CH₂)₂Sn}₂(𝜇-O)(OH)(𝜇-OH)]₂.2CH₂Cl₂ (5). Compounds 4 and 5 are dimeric tetraorganodistannoxanes consisting of a central distannoxane (Sn₂O₂) motif.