Аннотация:This paper reports a method for the synthesis of 1,1,3,3,5,5-hexamethyl-7,7-diorganocyclotetrasiloxanesby the interaction of 1,5-disodiumoxyhexamethylsiloxane with dichlorodiorganosilanessuch as methyl-, methylvinyl-, methylphenyl-, diphenyl- and diethyl dichlorosilanes. Dependingon the reaction conditions, the preparative yield of the target cyclotetrasiloxanes is 55–75%. Alongwith mixed cyclotetrasiloxanes, the proposed method leads to the formation of polymers with regularalternation of diorganosylil and dimethylsylil units. For example, in the case of dichlorodiethylsilane, 70% content of linear poly(diethyl)dimethylsiloxanes with regular alternation of units can be achieved in the reaction product. Using 7,7-diethyl-1,1,3,3,5,5 hexamethylcyclotetrasiloxane as an example, the prospects of the mixed cycle in copolymer preparation in comparison with the copolymerization of octamethyl- and octaethylcyclotetrasiloxanes are shown. РФФИ 20-33-70228