[reaction: see text] A newly developed strategy for eight-membered carbocycles via [3 + 4] annulation that involves the combination of beta-substituted acryloylsilanes and enolates of cycloheptenone is described. A unique feature of this annulative approach is its capacity to generate, in two steps, eight-membered ring systems containing useful functionalities for further synthetic elaboration from readily available three- and four-carbon components.