Intramolecular H-transfer reactions during the Decomposition of Alkylhydroperoxides in hydrocarbons as the solvents

Abstract

Eight defined primary and secondary alkylhydroperoxides were decomposed in n-alkanes as the solvent, mostly in the presence of manganese stearate. In all cases the corresponding alcohols and carbonyl compounds were formed as the main products with yields of 60-90 %. Besides, difunctional products were formed by an intramolecular H-transfer in the alkoxy radicals corresponding to the starting hydroperoxides. Products possibly formed by an intramolecular H-transfer in the corresponding alkylperoxy radical could be found only in the case of 4-methyl-2-hydroperoxy pentane. The amount of products formed by intramolecular H-transfer depended on the nature of the C-H bond in &position to the original hydroperoxy group and lay between 4 % (primary C-H in the case of 4-hydroperoxy heptane) and 13 % (tertiary C-H in the case of 2hydroperoxy-5-methyl hexane) with respect to the starting hydroperoxide.The amount of products formed by oxidative attack of the alkoxy and alkylperoxy radicals at the normal paraffins used as the solvents was unexpectedly low (always less than 10 % with respect to the starting hydroperoxide).An increment system is proposed for the calculation of I3C-nmr shifts in alkyl hydroperoxides. 'I) 3 m column with 10 % Triton X-I00 on Chromatone HMDS; 130 "C; 2.4 Ih-' H,: katharometer "proportion of heptane-1,4-diol to the sum of the nonanols

Study on Autoxidation Kinetics of Fats by Differential Scanning Calorimetry. 1. Saturated C12−C18 Fatty Acids and Their Esters

“…First publications 1,5 suggested that oxidative reactivity increased with an increase in the length of the carbon chain. Recent works , did not confirm this dependency, and the gross reactivities of the n -paraffins determined from the amount of the monofunctional derivatives were similar. Authors explained this discordance by probable formation of difunctional products of oxidation (not monitored in these experiments).…”

Synthesis of Mono- and Dinuclear Vanadium Complexes and Their Reactivity toward Dehydroperoxidation of Alkyl Hydroperoxides

“…In this work, vanadium­(V) complexes were identified as very promising homogeneous catalysts, as they form alkylperoxido complexes, − which, by intramolecular hydrogen transfer, release the corresponding alkyl ketone together with 1 equiv of water. Despite an unprecedented good selectivity for the conversion of 4-heptyl hydroperoxide to 4-heptanone at room temperature, the known competitive radical decomposition to a mixture of alcohol and ketone was still observed for cyclohexyl hydroperoxide.…”

Fenton-Inspired C–H Functionalization: Peroxide-Directed C–H Thioetherification

“…2-Hexyl mesylate (3.62 g, 20 mmol, 1 equiv) was subjected to general procedure C at a concentration of 0.3 M (12:1 MeOH/H 2 O) for 19 h. Silica flash chromatography provided 2-hydroperoxyhexane (879 mg, 37% yield) as a clear, colorless oil: 1 H NMR (600 MHz, CDCl 3 ) δ 7.69–7.54 (m, 1H), 4.06 (h, J = 6.1 Hz, 1H), 1.71–1.55 (m, 1H), 1.49–1.26 (m, 5H), 1.22 (d, J = 6.2 Hz, 3H), 0.90 (t, J = 7.0 Hz, 3H); 13 C­{ 1 H} NMR (100 MHz, CDCl 3 ) δ 81.9, 33.8, 27.7, 22.9, 18.3, 14.1; IR (neat) 3374, 2933, 2862, 1737, 1461, 1375, 1114 cm –1 ; TLC R f = 0.31 (15% EtOAc/hexanes).…”