PREPARATION AND SYNTHETIC UTILITY OF 1-TRIMETHYLSILOXYALKYL-BIS(TRIMETHYLSILYL)SILANES, (ME3SI)(2)SIH-C(OSIME3)(RR2)-R-1

1-Trimethylsiloxyalkyl-bis(trimethylsilyl) silanes (5), obtained by a base induced isomerization of easily accessable l-hydroxyalkyl-tris(tr imethylsilyl)silanes (1) were hydrolized to give 1-hydroxyalkyl-bis(tr imethylsilyl)silane (6), which in presence of sodium hydride underwent a further 1,3-Si,O-trimethylsilyl migration resulting in the formatio n of 1-trimethylsiloxyalkyl-disilanes Me3SiSiH2-C(OSiMe3)(RR2)-R-1 (7) Under acidic conditions, the alkoxysilanes 5 isomerized in a Me3Si/OS iMe3 exchange under formation of the 1-trimethylsilylalkyldisiloxanes 10, which were hydrolyzed affording the silanols 11. Chlorination of t he H-silanes 5 with CCl4 gave the chlorosilanes 12, which underwent ra pid thermal isomerizations to give via the 1-chloroalkyldisiloxanes 13 the 1-trimethylsilylalkyl-chlorodisiloxanes 15. Hydrolysis of 12 or 1 5, reap., finally afforded the 1-trimethylsilylalkyl-silanediols 18. P ossible mechanisms of the various isomerization processes are discusse d. The structures of the products described were elucidated by full sp ectral analyses. For 18a the results of an X-ray structural analysis a re given.