SILICON-DIRECTED BECKMANN FRAGMENTATION

Article abstract of DOI:10.1016/S0040-4020(01)81693-8

The selective fragmentation reactions of β-trimethylsilylketoximes have been proved to proceed effectively with acid catalysts giving the corresponding nitriles.Cyclic silylketoximes gave unsaturated nitriles.The fragmentation in the Beckmann rearrangement is completely controlled and directed by a trimethylsilyl group to lead the regio- and stereo-specific formation of the double bond.The catalytic fragmentation proceeds with the combination of trimethylsilyl ketoxime acetates and trimethylsilyl trifluoromethanesulfonate giving nitriles in high yields.Excellent stereospecificity of the fragmentation based on the stereochemical outcome was discussed.Simple stereo-controlled synthetic approach to some insect pheromones is also described.