Alkyl halides, hydroperoxide synthesis

Alkyl halides, hydroperoxide synthesis, 327-8 Alkyl hydroperoxides anion ligands, 114-19 covalent radii, 114, 118-19 dihedral angles, 119 geometric parameters, 115-8 tetrahedral distortion, 119 artemisinin formation, 133-4 chlorotriorganosilane reactions, 779-83 crystal structure, 105-14 anomeric effect, 110-11 geometric parameters, 106-9 hydrogen bonding, 103-5, 111-14 tetrahedral distortion, 110 determination, 674... 

Results of a chemical activation induced by ultrasound have been reported by Nakamura et al. in the initiation of radical chain reactions with tin radicals [59]. When an aerated solution of R3SnH and an olefin is sonicated at low temperatures (0 to 10 °C), hydroxystannation of the double bond occurs and not the conventional hydrostannation achieved under silent conditions (Scheme 3.10). This point evidences the differences between radical sonochemistry and the classical free radical chemistry. The result was interpreted on the basis of the generation of tin and peroxy radicals in the region of hot cavities, which then undergo synthetic reactions in the bulk liquid phase. These findings also enable the sonochemical synthesis of alkyl hydroperoxides by aerobic reductive oxygenation of alkyl halides [60], and the aerobic catalytic conversion of alkyl halides into alcohols by trialkyltin halides [61]. 

Literature procedures for the synthesis of hydroperoxides include the preparation from hydrogen peroxide (via reaction with alkyl halides, -phosphites, -suEonates, alkenes. 

SCHEME 7. Synthesis of hydroperoxides from electrochemically generated superoxide and alkyl halides... 

When primary alkyl phenyl tellurium or secondary alkyl phenyl tellurium compounds in methanol were treated with an excess of 3-chloroperoxybenzoic acid at 20, the phenyltelluro group was eliminated and replaced by a methoxy group. This reaction, which converts alkyl halides used in the synthesis of alkyl phenyl telluriums to alkyl methyl ethers, produced the ethers in yields as high as 90%3-4 Olefins are by-products in these reactions4 With ethanol as the solvent, ethyl ethers were formed. Other oxidizing agents (hydrogen peroxide, ozone, (ert.-butyl hydroperoxide, sodium periodate) did not produce alkyl methyl ethers. 

Control of the yields in the synthesis of alkyl peresters from the corresponding hydroperoxide and excess of acyl halide (equation 81) can be realized by RP-HPLC with DA-UVD or RID. The usual components of the analyte mixture are stable in the short retention times of the chromatographic runs (less than 4 min). The method was applied to control the synthesis of cumyl perbenzoate, perbutyrate and pervalerate. ... 

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