The reactions of cyclic siloxanes with acidic and basic reagents

Some ring opening reactions of cyclic siloxanes in organic solvents have been investigated. By the action of potassium hydroxide, hexaphenylcyclotrisiloxane and cis- and trans-trimethyltriphenylcyclotrisiloxane may all be converted into cyclotetrasiloxanes in good yield and, in the case of the latter two compounds, with a high degree of stereospecificity. By the action of hydrochloric acid, hexamethylcyclotrisiloxane is rapidly converted into octamethylcyclotetrasiloxane. The trimethyltriphenylcyclotrisiloxanes are much more resistant to the action of acids and conversion into cyclic tetramer is low.