Reactions of 2-chloroacyltrimethylsilanes with Grignard reagents have been examined. Thus, treatment with methylmagnesiumiodide affords the corresponding 3-(trimethylsilyl)-2-alkanones through an initial addition followed by removal of chloride anion and 1,2-rearrangement of silyl group. In contrast, the reaction proceeds with 2 equiv of the Grignard reagents bearing β-hydrogen to give 2-(trimethylsilyl)-1-alkanols