Cyclopentene, autoxidation

The major product from the former is cyclohexen-3-one, along with minor amounts of cyclohexene oxide (17). Epoxide formation has also been identified as a minor product from cyclopentene autoxidation. The intermediacy of 3-cyclohexene hydroperoxide was proposed in this report but not verified/ Subsequent work on the autoxidation of cyclohexene using RhCl(PPh3)3 verified this premise/ and a number of review articles have emphasized this conclusion.The involvement of preformed hydroperoxide has been verified by comparing the rate of cyclohexene oxidation both with hydroperoxide present, and also when the cyclohexene is purified free from peroxide. In the former case the reaction is rapid and there is no induction period. Under conditions where the cyclohexene is peroxide free the reaction proceeds more slowly, and there is an induction period of close to three hours (using IrCl(CO)(PPh3)2 as catalyst) as the hydroperoxide intermediate is being performed (18) ... 

Oxidation of Ozonolysis Products from 1-Octene and 1-Methyl-cyclopentene. Uncatalyzed autoxidation was performed in a small vessel... 

Autoxidation of cyclohexene is mediated by 812(804)3 to give 1-cyclopentene-l-carboxylic acid in 90-92% yield [232], The selective oxidation of sulfides to sulfoxides is accomplished by Bi(NO3)3, both stoichiometrically [233] and catalytically with air [234]. 

An autoxidative procedure has been described by the initial alkylation of phenol with cyclopentadiene in the presence of phosphoric add at ambient temperature giving 4-(cyclopenten-2-yl)phenol, in more than 80% yield followed by isomerisation in 91% yield to the 1-isomer during 2 hours in refluxing benzene solution with a catalytic quantity of dichlorobis(benzonitrile)palladium(ll). The conjugated product with 30% hydrogen peroxide and hydrochloric add upon stirring at 50°C for 3 hours afforded 1,4-dihydroxybenzene in 92% yield accompanied by cyclopentanone (ref.46). 

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