Reactions of Silicon Alkoxides with Phthalic and Succinic. Anhydrides

Reactions of ethyl orthosilicate and isopropyl orthosilicate with phthalic and succinic anhydrides show that the reaction in 1:1 molar ratio affords the trialkoxy monophthalate or trialkoxy monosuccinate derives, but, when the alkoxides and acid anhydrides are taken in molar ratio of 1:2, the end product is always dialkoxysilicon diphthalate or disuccinate derivative.