C-NITROSO COMPOUNDS-XXXV REACTION OF ORGANOMETALLIC COMPOUNDS WITH 1-CHLORO-1-NITROSO-2,2,6,6-TETRAMETHYLCYCLOHEXANE

Article abstract of DOI:10.1016/0040-4020(80)80085-8

Reaction of Grignard reagents and organolithium compounds (RM) with the congested 1-chloro-1-nitroso-2,2,6,6-tetramethylcyclohexane 1 leads to the formation of significant amounts of the reduction product 2,2,6,6-tetramethylcyclohexanone oxime 3 (61-90percent) together with the corresponding oxime O-R ether 4 (0-11percent).Attack on nitrogen is unimportant as shown by very low yields of nitrone.Formation of the products is rationalised with a pathway involving transfer of an electron from RM to 1.This leads-after separation of MCl-to a radical pair consisting of R^. and the relatively stable iminoxy radical 2 (Schemes 1 and 2).Combination of these radicals explains formation of oxime ether 4 and nitrone 5, while reaction of iminoxy radical 2 with excess of RM can give oxime 3.Reactive radicals R^. (i.e.Me,Ph, and to a minor extent n-Bu) are furthermore capable of abstracting hydrogen from the solvent (diethyl ether, toluene, or cumene), and the solvent derived radicals can also combine with 2 on oxygen, under formation of oxime ether (26percent of 6a).The corresponding benzyl- and cumyl ethers 6b and 6c are only formed in trace amounts because dimerisation of benzyl radicals (7percent) and cumyl radicals (22percent) is favoured.