Trimethylsilyl group Beckmann fragmentation

Silyl-directed Beckmann fragmentation. A trimethylsilyl group in the p- or p -position of cyclic ketoxime acetates controls the regio- and stereochemistry of the double bond formed on Beckmann fragmentation catalyzed by trimethylsilyl triflate. 

Silyl-directed Beckmann fragmentation.19 A trimethylsilyl group in the P- or p -... 

The trimethylsilyl group can rigorously control and direct the Beckmann fragmentation leading to the regio- and stereo-specific formation of unsaturated nitriles (equations 41 to 43). Oxime acetate (57) fragments to the cij-alkenic nitrile (58) in 90% yield, whereas its epimer (59) affords the franj-alkenic nitrile (60) in 94% yield under the same conditions. Furthermore, fluoride-induced fragmentation can re-... 

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