Hydroxymethylation of silanol-terminated

It is known that the synthesis of carhinol-terminated polysilox-anes starting from hydroxy-terminated polysiloxanes may he disturbed hy occurrence of competitive depolymerization and condensation processes (1). This is due to the rather harsh reaction conditions (2), since the established synthetic procedures for the hydroxymethylation of hydroxy polysiloxanes require either the presence of acidic/basic catalysts (3), Lewis acids (4) or the prior transformation into Grignard reagent (5). Cyclic alkoxy silanes are very useful reagents for a facile and mild introduction of the hydroxymethyl function into a silanol-terminated polysiloxane. 

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