The reaction between hydrated copper nitrate and tetraethoxysilane was followed by Si-29 NMR. The reaction was fast at room temperature even with no acid added to the reaction medium. The necessary catalysis was provided by the hydrated copper ions, which are strongly acidic in the alcohol medium releasing two protons for each hydrated copper ion. The NMR spectra gave signal positions of the different silicon compounds distinctly different from those reported from the reaction in alcohol between tetraethoxysilane and water of low pH. The NMR signals were given assignments and preliminary information obtained about the reaction path.