Hydrogen peroxide reactions with aldehydes

Methylenecyclohexane oxide has been prepared by the oxidation of methylenecyclohexane with benzonitrile-hydrogen peroxide or with peracetic acid by treatment of 1-chlorocyclo-hexylmethanol with aqueous potassium hydroxide and by the reaction of dimethylsulfonium methylide with cyclohexanone. This reaction illustrates a general method for the conversion of ketones and aldehydes into oxiranes using the methylene-transfer reagent dimethyloxosulfonium methylide. The yields of oxiranes are usually high, and the crude products, in most cases, are of sufficient purity to be used in subsequent reactions (e.g., rearrangement to aldehydes) without further purification. 

The acid reaction has been used in cases in which complications have been noted with the alkaline hydrogen peroxide reaction. Thus, l,l-bis(boronates) smooAly yield aldehydes and l,2-bis(boronates) give... 

The a-hydrogens of nitroalkanes are appreciably acidic due to resonance stabilization of the anion [CH3NO2, 10.2 CH3CH2NO2, 8.5]. The anions derived from nitroalkanes give typical nucleophilic addition reactions with aldehydes (the Henry-Nef tandem reaction). Note that the nitro group can be changed directly to a carbonyl group via the Nef reaction (acidic conditions). Under basic conditions, salts of secondary nitro compounds are converted into ketones by the pyridine-HMPA complex of molybdenum (VI) peroxide. Nitronates from primary nitro compounds yield carboxylic acids since the initially formed aldehyde is rapidly oxidized under the reaction conditions. 

Sulfoxides (1) may be oxidised to sulfones by treatment with hydrogen peroxide (in acetic acid) or peroxycarboxylic acids (see Chapter 10, p. 195). Sulfoxides can also be reduced to sulfides by powerful reducing agents, e.g. lithium aluminium hydride. The reduction can also be achieved by reaction with dichloroborane (13) in THF at 0°C without affecting other functional groups like C02R, COCI, CN or N02, and even side reactions with aldehyde and ketone groups are relatively slow (Scheme 8). 

AMYL-METHYL-CETONE (French) (110-43-0) Forms explosive mixture with air (flash point 102°F/38°C). Violent reaction with strong oxidizers, aldehydes, nitric acid, perchloric acid. A variety of unstable peroxides may be formed from the reaction with hydrogen peroxide. Incompatible with aliphatic amines, aldehydes, strong bases, hydrogen peroxide, nitric acid, perchloric acid. Attacks some plastics and rubber. 

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