Allyl difluorovinyl ethers rearrangement

A number of Claisen rearrangements of allyl vinyl ethers have been reported. Thus allyl 2-diloro-l,2-difluorovinyl ether, prepared by the alkoxide-catalysed addition of allyl alcohol to chlorotrifluoroethylene, followed by dehydrofluoiination with n-butyl-lithium at —SO °C, rearranges at-35 C ... 

Scheme 10.36 Claisen rearrangements of difluorovinyl allyl ethers with sulfurcontaining boron catalyst.

The scope of this methodology was extended to the enantioselective rearrangement of difluorovinyl allyl ethers by these authors, furnishing a novel powerful tool for the synthesis of chiral p-substituted a,a -difluorocarbonyl compounds. As shown in Scheme 10.36, moderate to good enantioselectivities... 

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