1. A study was made of the oxidation of secondary γ-silicoacetylenic alcohols using chromic anhydride in sulfuric acid, and also Beckmann's oxidizing mixture, and a method for the preparation ofa- silicoacetylenic ketones in up to 95% yield was proposed on the basis of this reaction. 2. The bromination of the γ-silicoacetylenic ketones was studied. It proceeds stepwise, with the predominant formation of α,β-dibromoethylene ketones. The addition of a second bromine molecule proceeds with difficulty, and bromination of the organic radicals attached to the silicon atom is not observed here.