N-nitroso groups

The discovery of the anchimeric effect of the N-nitroso group led to several exciting possibilities. Kruger (12) postulated that if the side chain of nitrosamines is larger than ethyl, the compounds are degraded to methylating agents by B-hydroxyl-ation. He postulated that the function of this side chain... 

These rates are some four orders of magnitude slower than tosyl-ate I and even the highly reactive benzyl tosylate is slower by a factor of 200 than I. It is also noteworthy that whereas tosylate I solvolyses substantially more rapidly than III, the solvolysis of the latter is also accelerated significantly. The extremely fast rate of solvolysis for compounds I and II demand that the N-nitroso group be involved in the reaction, which we postulated to take the following course. 

Solvolysis of the optically active tosylate IV provided further data to substantiate the intermediate formation of V. If the N-nitroso group did not become involved in the solvolysis, then the product would show either inversion of configuration or race-mization. If, on the other hand, V was an intermediate then the product should show retention of configuration. This was indeed found to be the case, the product acetate had exactly the same configuration as the starting material IV. This result is summarized in the following scheme. 

Cox, R. D. (1980). Development of analytical methodologies for parts per billion level determination of nitrate, nitrite, and N-nitroso group content. Ph.D. dissertation. University of Iowa. 

Extensive study has been made of the modes of aqueous decomposition of BCNU, at least in part for the purpose of elucidating its mechanism of antitumor activity (24-28). Montgomery and coworkers foimd that N2 was quantitatively evolved during aqueous decomposition of the drug and used nitrogen production as the measure of rate of reaction (24). Furthermore, all aqueous decomposition schemes proposed to date for BCNU place the N-nitroso group in unstable intermediates (e.g., diazohydroxides) from which N2 is promptly evolved (16,24-30). 

A nitro group in the 2 position is more easily reduced than a group in the 4 position. As to the reduction of nitroso groups, it emerges that a C-nitroso group is much easier reduced than a N-nitroso group. 

Nitroquinoline, 435 8-Nitroquinoline, 435 4-Nitroquinoline N-oxide, 437 Nitrosamine, 156, 203-220, 398 A -Nitrosoanatabine, 204 -Nitrosobis(2-oxopropyl)amine, 204 -Nitrosodibenzylamine, 214 Nitrosodiethanolamine, 204 N-Nitroso group, 414 N-Nitroso-2- hydioxymorpholine, 216 N-Nitrosomorpholine, 205, 214, 216 N -Nitrosonomicotine, 204, 205, 214, 217-220 N -Nitrosonomicotine 1-N-oxide, 217 Nitrosophenol, 38... 

The chiral auxiliary may be recycled without difficulty simply by mild reduction of the N-nitroso group. 

Poecillanosine is one of the very few examples of natural derivatives with a N-nitroso group. This molecule was isolated from the species PoecUlastra aff. tenuilaminaris, and has antiradical and cytotoxic properties for leukemia P388 with a ID50 of 1.8 xgml (Natori et al., 1997). 

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