84619-17-0Relevant articles and documents
Iron-catalyzed Autoxidation of Cholesterol in the Presence of Unsaturated Long-Chain Fatty Acid
Muto, Toshiki,Tanaka, Jun,Miura, Toshiaki,Kimura, Michiya
, p. 3172 - 3177 (2007/10/02)
Oxy-functionalization of cholesteryl acetate (1a) occured, giving 3β-acetoxy-5,6-epoxycholestane (2a), 3β-acetoxycholest-5-en-7-one (3a), 3β-acetoxycholest-5-en-7-ol (4a), and an unidentified product (5), when 1a was oxidized by a system consisting of Fe(acac)3, and the hydroperoxide of an unsaturated long-chain fatty aicd (LH) such as oleic, linolic or linolenic acid (Table I).The epoxidation of stilbene by the same system was found to be non-stereospecific.These results and the fact that the reaction in this system was inhibited by a radical scavanger (BHT) were fairly compatible with those obtained with the Fe(acac)3-tBuOOH system, which is assumed to generate oxy and peroxy radicals.Autoxidation of 1a and cholesterol (1b) in the presence of Fe(acac)3 and LH proceeded after a time-lag of several hours and was also inhibited be BHT.The marked stereoselectivity of β-epoxidation (β/α+β=0.72) and the extent (about 30-40percent) of allylic oxidation in the autoxidation were in fair agreement with those found for 1a in the Fe(acac)3-LOOH system (Table II).Autoxidation of stilbene in the presence of Fe(acac)3 and LH also led to non-stereospecific epoxidation.Thus, the autoxidation of cholesterols (1a and 1b) in the Fe(acac)3-LH system was assumed to be a radical reaction in which LOO. and LO. are the attacking species.Keywords - autoxidation; cholesterol; co-oxidation; epoxidation; hydroperoxide; lipid peroxidation; radical pathway; stilbene; tris(acetylaceto)iron(III); unsaturated long-chain fatty acid
