2,2,5,5,-Tetramethyl-2,5-disila-1,3-dioxolan und Verfahren zu seiner Herstellung

2,2,5,5 - Tetramethyl - 2,5 - disila - 1,3 - dioxolan of the formula may be prepared by two methods. One method comprises heating a mixture of equimolar amounts of 1,3 - di - (hydroxymethyl) - tetramethyldisiloxane and 1,3 - di(bromomethyl)-tetramethyl disiloxane and excess methylamine until salt precipitation is complete, removing the nitrogen compounds from the mixture, adding p-toluene sulphonic acid as catalyst, distilling under reduced pressure and recovering the product as the distilate. The second method comprises heating a mixture of equimolar amounts of dimethyl - (acetoxymethyl)-acetoxysilane and dimethyldiethoxysilane, 5-20 fold molar amount of methanol and p-toluene sulphonic acid as catalyst, distilling off methanol, ethanol and methyl acetate, and then distilling under reduced pressure and recovering the product as the distillate. Hydrolysis of the product alone gives 1,7-di-(hydroxymethyl)-octamethyltetrasiloxane and cohydrolysis with organoalkoxysilanes gives organopolysiloxanes with terminal hydroxymethyl groups. Copolymerization with trioxan gives polyoxymethylenes with siloxane segments.