2,2-dimethyldioxirane

In general, peroxomonosulfates have fewer uses in organic chemistry than peroxodisulfates. However, the triple salt is used for oxidizing ketones (qv) to dioxiranes (7) (71,72), which in turn are useful oxidants in organic chemistry. Acetone in water is oxidized by triple salt to dimethyldioxirane, which in turn oxidizes alkenes to epoxides, polycycHc aromatic hydrocarbons to oxides and diones, amines to nitro compounds, sulfides to sulfoxides, phosphines to phosphine oxides, and alkanes to alcohols or carbonyl compounds. 

In the mid-1980s a convenient and relatively safe procedure was developed for vacuum codistillation of dimethyldioxirane and acetone from acetone—caroate systems (107). The resulting acetone solution of dimethyldioxirane could be used in subsequent oxygenation reactions (92). 

This ether, developed for the protection of a pyranoside anomeric hydroxyl, is prepared via a Konigs-Knorr reaction from the glycosyl bromide and 2-(ben-zylthio)ethanol in the presence of DIPEA. It is cleaved, after oxidation with dimethyldioxirane, by treatment with LDA or MeONa. ... 

Dimethyldioxirane, acetone, 48 h, rt, 85-93% yield. p-Bromo-, p-cyano- and 2-naphthylmethyl ethers, and benzylidene acetals can also be deprotected. 

Dimethyldioxirane, acetone, CH2CI2, 0°, 24 h, > 95% yield. Ethers are also oxidized under these conditions. 

Fullerene epoxide, C )0, is formed by the UV irradiation of an oxygenated benzene solution of Cfio The O atom bridges a 6 6 bond of the closed fullerene structure. The same compound is also formed as one of the products of the reaction of Cgo with dimethyldioxirane, Mc2COO (see later). ... 

A modern reagent, that has found increased application, is dimethyldioxirane it is prepared in situ by oxidation of acetone with potassium peroxomonosul-fate KHSOs. ... 

Dimethyldioxirane oxidation of nitronaies anions affords the correspondmg carbonyl products. Highest yields are obtained when one equivalent of water Is added before the oxidation fEq. 6.9). ... 

Dimethyldioxirane DMDO discovered by Murray and coworkers, is a superior choice for the epoxidation of most olefins, giving comparable or higher yields than m-CPBA-based epoxidation [21]. Proceeding rapidly under neutral and mild conditions, it is especially well suited for the synthesis of sensitive epoxides of enol esters, enol lactones [22], and enol ethers [23]. The reaction is stereospecific, gen-... 

The most widely employed methods for the synthesis of nitrones are the condensation of carbonyl compounds with A-hydroxylamines5 and the oxidation of A+V-di substituted hydroxylamines.5 9 Practical and reliable methods for the oxidation of more easily available secondary amines have become available only recently.10 11 12 13. These include reactions with stoichiometric oxidants not readily available, such as dimethyldioxirane10 or A-phenylsulfonyl-C-phenyloxaziridine,11 and oxidations with hydrogen peroxide catalyzed by Na2W044 12 or Se02.13 All these methods suffer from limitations in scope and substrate tolerance. For example, oxidations with dimethyldioxirane seem to be limited to arylmethanamines and the above mentioned catalytic oxidations have been reported (and we have experienced as well) to give... 

Dimethyldioxirane was prepared according to the literature procedure2 as an 0.08M solution and was dried over 4a beaded molecular sieves for 24 hr prior to use. 

Expedient removal of the volatiles after the epoxidation with dimethyldioxirane is crucial to achieve reproducible yields because the epoxide is extremely water sensitive. 

Secondary amines (R2NH) are oxidized to hydroxylamines (R2NHOH), which are resistant to further oxidation, by dimethyldioxirane and by benzoyl peroxide and NajHPOa. " ... 

Epoxidation by Dioxirane Derivatives. Another useful epoxidizing agent is dimethyldioxirane (DMDO),86 which is generated by in situ reaction of acetone and peroxymonosulfate in buffered aqueous solution. Distillation gives about aO.lM solution of DMDO in acetone.87... 

Analyze the following data on the product ratios obtained in the epoxidation of 3-substituted cyclohexenes by dimethyldioxirane. What are the principal factors that determine the stereoselectivity ... 

PhMe2Si)3CSiH2OH and subsequent reaction with two equivalents of dimethyldioxirane to give (PhMe2Si)3CSi(OH)3 (310). 

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