108100-70-5Relevant articles and documents
CYCLOADDUCTS OF C-NITROSOCARBONYL COMPOUNDS AND ERGOSTERYL ACETATE; SIGMATROPIC REARRANGEMENTS OF N-AROYL-3,6-DIHYDRO-1,2-OXAZINES
Kirby, Gordon W.,Mackinnon, John W.M.
, p. 887 - 892 (2007/10/02)
Oxidation of acetohydroxamic acid with tetraethylammonium periodate in the presence of ergosteryl acetate (3) gave a single cycloadduct (4a) arising from 1,4-addition of the nitroso group of nitrosocarbonylmethane to the diene system of (3).In contrast, nitrosocarbonylbenzene, generated by oxidation of benzohydroxamic acid or by thermal dissociation of the 9,10-dimethylanthracene adduct (12; R=Ph), gave two 1,4-adducts, (4b) and (5b), with (3).The adduct (5b) isomerised at 60 deg C to give a dioxazine (6b), formally an adduct of nitrosocarbonylbenzene, acting as a 4?-electron component, with the 5,6-double bond of (3).However, the isomerisation still took place in the presence of triphenylphosphine, an efficient trap for C-nitroso-compounds, and must therefore have occured by an intramolecular, sigmatropic rearrangement. 4-Bromo-, 4-methoxy-, and 4-nitro-nitrosocarbonylbenzene reacted similarly with (3) whereas 2,4,6-trimethylnitrosocarbonylbenzene gave (4f) as the sole adduct.Adducts of pyrocalciferyl acetate (21) and isopyrocalciferyl acetate (22) with nitrosocarbonylbenzene and of ergosteryl acetate with the nitrosoimine (26) have also been prepared.
