Dimethyldioxirane preparation

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. ... 

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 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. 

Aliphatic and aromatic primary amines are rapidly and efficiently oxidized to nitro compounds by dimethyldioxirane.111 Dimethyldioxirane is prepared by reaction of OXONE (DuPont trademark)-2KHS05-KHS04-K2S04 with buffered aqueous acetone.112... 

The preparation of 2,3,5-trisubstituted 4,5-dihydrofurans 81 with complete regio-control can be realized by an one-pot transformation involving epoxidation of 2-alkenyl-1,3-dicarbonyls by in situ generated dimethyldioxirane, and is followed by a S-exo-ieX intramolecular nucleophilic cyclization under the same basic condition <00TL10127>. 

The synthesis, X-ray structure and solid state NMR of 4,4-dimethyl-l,2-ditellurolane 75 have been reported <98PS(136-8)291>. Chemoselective oxidation of 1,2-dithiole derivatives using dimethyldioxirane to give products such as 76 has been described <00SUL169>. Cycloaddition of dihydroquinoline-fused l,2-dithiole-3-thiones 77 with DMAD gives the spiro 1,3-dithioles 78 <99CHE587>. Dicationic thiatelluroles such as 79 have been prepared <00AG(E)1318>, anti cancer properties have been claimed for the simple dithiolopyrrolones... 

Polymer-supported permthenate has also been used in two convergent pathways for the synthesis of isoxazoUdines with each route employing different starting materials in order to create the maximum structural diversity [73]. In the first route secondary hydroxylamines, readily prepared from amines by in situ treatment with dimethyldioxirane, were oxidized directly to nitrones using polymer-supported permthenate (PSP). Alternatively, primary alcohols were used as the... 

Primary, secondary and tertiary aliphatic amines are efficiently converted to nitro compounds in 80-90 % yield with dimethyldioxirane, a reagent prepared from the reaction of oxone (2KHSO5-KHSO4-K2SO4) with buffered acetone. Dimethyldioxirane (DMDO) has been used for the synthesis of 1,3,5,7-tetranitroadamantane (71) from the corresponding tetraamine as the tetrahydrochloride salt (70) and is an improvement over the initial synthesis using permanganate anion (Table 1.7). ° Oxone is able to directly convert some aromatic amines into nitro compounds. 

Dimethyldioxirane is a powerful oxidant prepared by reacting acetone with KHSOs the latter is commercially available as a triple salt under the trade name of oxone. 1,4-Dinitrocubane... 

CgoO (1) can also be prepared by allowing toluene solutions of CgQ to react with dimethyldioxirane (Scheme 8.3) [28], The so-obtained product is identical to that prepared by photochemical epoxidation [15], Upon treatment of CgQ with dimethyldioxirane, a second product is formed simultaneously (Scheme 8.3), which was identified to be the 1,3-dioxolane 6. Upon heating 6 in toluene for 24 h at 110 °C, no decomposition could be observed by HPLC, implying that 1 and 6 are formed by different pathways. Replacement of dimethyldioxirane with the more reactive methyl(trifluoromethyl)dioxirane allows much milder reaction conditions [29]. At 0 °C and a reaction time of only some minutes this reaction renders a CgQ conversion rate of more than 90% and higher yields for CgoO as well as for the higher oxides. 

The synthetically most useful method for the preparation of dioxiranes is the reaction of appropriate ketones (acetone, trill uoroacetone, 2-butanone, cyclohexanone etc.) with Caroate, commercially available as the triple salt of potassium monoperoxysul-fate (KHSOs). The catalytic cycle of the dioxirane formation and oxidation is shown in Scheme 1 in general form. For acetone as the ketone, by simple distillation at a slightly reduced pressure ca 100 torr) at room temperature ca 20 °C), Jeyaraman and Murray successfully isolated dimethyldioxirane (DMD) as a pale yellow solution in acetone (maximally ca 0.1 M). This pivotal achievement in 1985 fomented the subsequent intensive research activity in dioxirane chemistry, mainly the synthetic applications but also the mechanistic and theoretical aspects. The more reactive (up to a thousandfold ) fluorinated dioxirane, methyl(trifluoromethyl)dioxirane (TFD), was later isolated in a similar manner by Curd, Mello and coworkers". For dioxirane derived from less volatile ketones, e.g. cyclohexanone, the salting-out technique has been developed by Murray and coworkers to obtain the corresponding dioxirane solution. 

Dimethyl-1,2-dioxetanone, chemiluminescence quantum yield, 1226-7 Dimethyldioxirane epoxidation atkenes, 37-44 deuteriation, 1143 O NMR spectroscopy, 184-5 preparation, 26, 1130-2 structure, 26... 

Acetyl-protected 1,2,3,4-tetrahydropyrazines 105, which are prepared by treatment of 2,3-dihydropyrazine with acetic anhydride and zinc (Scheme 27), undergo photooxidation to produce new dioxetanes 106 <1995JA9690>. Upon thermolysis, the dioxetanes 106 decompose quantitatively to tetraacyl ethylenediamines 107. Dimethyldioxirane oxidation of tetrahydropyrazine 105 affords novel epoxide 108, which is also generated by deoxygenation of dioxetane 106 with dimethyl sulfide. In 2,3,4,5-tetrahydropyrazine 1-oxide 109, which is prepared... 

The preparation of the allene bis-epoxide 1 started with isovaleraldehyde 9. Addition of the protected propargyl alcohol 10 under the Carreira conditions led to 11 in > 95% . Mesylation followed by displacement with methyl cuprate provided the allene without loss of enantiomeric excess. Oxidation of the allene 12 with dimethyldioxirane could have led to any of the four diastereomers of the spiro bis epoxide. In the event, only two diastereomers were observed, as a 3 1 mixture. That 1 was the major diastereomer followed from its conversion to 3. The configuration of the minor diastereromer was not noted. Exposure of 1 to nucleophilic azide then gave the easily-purified 2. 

Tertiary alkyl primary amines can be oxidized to nitro compounds in excellent yields with KMn04.39S This type of nitro compound is not easily prepared in other ways. All classes of primary amine (including primary, secondary, and tertiary alkyl as well as aryl) are oxidized to nitro compounds in high yields with dimethyldioxirane.399 Other reagents that oxidize various types of primary amines to nitro compounds are dry ozone,4,111 various peracids,401 including peracetic and peroxytrifluoroacetic acids, f-butyl hydroperoxide in the presence of certain molybdenum and vanadium compounds,402 F7-H20-MeCN,41123 and sodium perborate.403... 

As a reagent, it is commonly found in the preparation of dimethyldioxirane (DDO). itself a useful oxidizing agent. 

Polymer modification is of particular interest when the desired polymer is not readily available from its corresponding monomer by conventional polymerization methods. The primary challenge of polymer modification is to achieve a high conversion and selective modification of the appropriate functional group. In this paper, we describe a new convenient polymer modification to prepare novel silanol polymers by a rapid and selective oxidation of the Si—H bond with a dimethyldioxirane solution in acetone from their corresponding precursor polymers. 

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