Tetramethyl orthosilicate hydrolyzes to SiO2: In organic synthesis, Si(OCH3)4 has been used to convert ketones and aldehydes to the corresponding ketals and acetals, respectively. ==Safety== The hydrolysis of Si(OCH3)4 produces insoluble SiO2 and CH3OH (methanol). Even at low concentrations inhalation causes lung lesions, and at slightly higher co...