Prepd by hydrolysis of dimethyldichlorosilane and trimethylchlorosilane: Patnode, Wilcock, J. Am. Chem. Soc. 68, 358 (1946); by reaction of hexamethyldisiloxane with octamethylcyclotetrasiloxane and sulfuric acid: eidem, ibid. 362; Patnode, US 2469888 (1949 to General Electric); by cohydrolysis of ethoxytrimethylsilane and diethoxydimethylsilane: Hunter et al., J. Am. Chem. Soc. 68, 2284 (1946); Hyde, US 2457677 (1948 to Corning Glass).