Method for the preparation of alkoxysilane cluster compounds

Claim 1

In a method for preparing an alkoxysilane cluster compound of the formula: ##STR4## wherein R is hydrogen, alkyl, alkenyl, aryl or aralkyl, and each R' is independently selected from alkyl, alkenyl, aryl or aralkyl with the proviso that at least a majority of R' radicals are sterically hindered alkyl groups having at least 3 carbons atoms, comprising reacting a trihalosilane of the formula: R--SiX.sub.3 wherein each X is a halogen and R is as defined above, with a trialkoxysilanol of the formula: HOSi(OR').sub.3 wherein R' is as defined above, in the presence of an acceptor base compound, an improvement characterized by reacting about 2.8 to about 3.3 moles of trialkoxysilanol per mole of the trihalosilane in the presence of about 3.5 to about 4.5 moles of acceptor base per mole of trihalosilane, in a non-protonic solvent medium comprising about 0.8 to about 1.8 parts solvent per part total reactants by volume, said reaction being carried out at a temperature of about -5° C to about 60° C.