Divergent Synthesis of gem-Difluoro-2-oxabicyclo[2.1.1]hexanes Enabled by 1,3-Oxygen Rearrangement

We present a visible light photocatalytic strategy for efficient synthesis of gem-difluoro-2-oxabicyclo[2.1.1]hexanes through cross [2 + 2] cyclization of γ,γ- and α,α-difluoroallyl vinyl ethers, which represent a class of novel hybrid bioisosteres. This method demonstrates notable advantages, including visible light photocatalysis, readily available starting materials, and high operational efficiency. A distinctive feature involves the 1,3-oxygen rearrangement capacity of γ,γ-difluoroallyl vinyl ethers to their α,α-difluorinated isomers, enabling access to both diF-2-oxa-BCH isomers from 3,3-difluoroallyl alcohols. The protocol's practicality is underscored by successful gram-scale implementation with maintained excellent yields, suggesting significant potential for pharmaceutical applications.