Angle-Strained Cycloalkyne-Mediated Carbonyl 1,2-Transposition

Carbonyl 1,2-transposition represents a powerful yet challenging transformation in molecular editing, enabling the precise repositioning of ketone functionalities within carbocyclic frameworks. While this approach holds significant promise for streamlining synthetic routes and tailoring molecular properties, efficient methods for relocating carbonyls in five-membered ring substrates remain an unmet challenge. Here we report a strain-release-driven strategy for the one-pot translocation of carbonyl moieties within prevalent cyclic ketones. This method exploits the pronounced reactivity of angle-strained cycloalkynes, generated in situ directly from accessible cyclic ketones, which then undergo regioselective 1,2-addition followed by hydrolysis to yield the desired carbonyl-migrated products. By harnessing the intrinsic strain energy of small-ring cycloalkynes to facilitate a fundamental functional-group transposition, this work provides rapid access to complex structures and natural product analogues through late-stage functionalization. A strain-release-driven, one-pot carbonyl 1,2-transposition of ubiquitous cyclic ketones is reported. This operationally simple method leverages highly strained cycloalkyne intermediates generated in situ, enabling broad substrate scope and late-stage structural editing of natural products and pharmaceuticals.