Stereoselective construction of eight-membered oxygen heterocycles by Brook rearrangement-mediated [3 + 4] annulation

[reaction: see text] A newly developed strategy for eight-membered oxygen heterocycle construction via [3 + 4] annulation is described. The method involves the combination of beta-substituted acryloylsilanes and enolates of 6-oxacyclohept-2-en-1-one. A unique feature of this annulative approach is its capacity to generate eight-membered ring systems containing useful functionalities for further synthetic elaboration from readily available three- and four-carbon components.