THE FIRST TRIALKOXYSILANES AND TETRAALKOXYSILANES WITH 4 DIFFERENT SUBSTITUENTS

Unsymmetrically substituted tri- and tetraalkoxysilanes were surprisin gly found to be configurationally stable and easy to prepare. It was f ound that compounds of type MeSi(OR)(2)(OR'), MeSi(OR)(OR')(OR ''), Si (OR)(2)(OR')(2), Si(OR)(2)(OR')(OR ''), Si(OR)(3)(OR'), and even Si(OR )(OR')(OR '')(OR) could be obtained by sequential addition of a varie ty of chiral and achiral alcohols to methyltrichlorosilane or tetrachl orosilane in the presence of pyridine. In the case of MeSi(OR)(OR')(OR '') and Si(OR)(OR')(OR '')(OR), two types of compounds that have nev er been prepared before, were obtained in good yield.