ONE-STEP SYNTHESIS OF DIAZIRINES FROM O-TOSYL KETOXIMES AND ALKOXYAMINES

Article abstract of DOI:10.1007/BF00503487

The reaction of O-tosyloximes of acetone, hexafluoroacetone, and mesoxalic acid esters with alkoxyamines leads to the corresponding diazirines, while the reaction of benzophenone O-tosyloxime with methoxyamine gives only benzophenone O-methyloxime.O-Esters of acetoxime were isolated along with 3,3-dimethylazirine also in the reaction of O-tosylacetoxime with alkoxyamines.Nucleophilic attack of alkoxyamines on O-tosyloximes of mesoxalates is realized at the carbon atom of not only the C=O bond but also at the carbon atom of the C=O bond, and the latter leads to fragmentation of the O-tosyloxime to give N-alkoxycarbamates, a cyanocarbonate ester, and p-toluenesulfonic acid.In the presence of triethylamine, which blocks the C=N bond, the reaction of mesoxalate O-tosyloxime proceeds only via the fragmentation pathway.The mechanism of the formation of diazirines in the reaction of O-tosylketoximes with alkoxyamines is discussed.