Oxidation of esters

VS Martemyanov. Kinetics and Mechanism of High-Temperature Oxidation of Esters of Polyatomic Alcohols. Doctoral Thesis Dissertation, Institute of Chemical Physics, Chernogolovka,... 

The rare example of synergistic action of a binary mixture of 1-naphthyl-A-phcnylaminc and phenol (1-naphthol, 2-(l,l-dimethylethyl)hydroquinone) on the initiated oxidation of cholesterol esters was evidenced by Vardanyan [34]. The mixture of two antioxidants was proved to terminate more chains than both inhibitors can do separately ( > /[xj). For example, 1-naphtol in a concentration of 5 x 10 5 mol L-1 creates the induction period t=170s, 1 -naphthyl-A-phenylamine in a concentration of 1.0 x 10-4 mol L 1 creates the induction period t = 400s, and together both antioxidants create the induction period r = 770 s (oxidation of ester of pelargonic acid cholesterol at 7= 348 K with AIBN as initiator). Hence, the ratio fs/ZfjXi was found equal to 2.78. The formation of an efficient intermediate inhibitor as a result of interaction of intermediate free radicals formed from phenol and amine was postulated. This inhibitor was proved to be produced by the interaction of oxidation products of phenol and amine. 

Tab. 5 Remote oxidation of esters in acetonitrile/LiCl04 or TEABF4 ...

Model of Deterioration Mechanisum, As acetyl content decreases due to hydrolysis or oxidation of ester bonding, solute permeability increases. Then concentration of solute( in this case sodium hypochlorite) in the membrane increases and the hydrolysis or oxidation rate increases and so on. It will be more reasonable to assume that hydrolysis or oxidation rate of cellulose acetate in the active surface layer may be accelerated by the action of the nascent oxygen generated from sodium hypochlorite. 

Oxidation of esters of cephalosporin V (368) with 4-(ert-butyl(difluoroi-odo)benzene in CH3CN leads to the formation of oxazoline disulfides 369. This is an example where cyclization occurring by intramolecular participa-... 

Oxidation of esters of a-amino acids. These substrates are oxidized by the Mitsunobu reagent (1) at the a-position to give either a-keto esters or adducts. For example, the N-benzyloxyphenylglycine methyl ester 2 is oxidized to methyl phenylglyoxalate 3 in 93% yield. In contrast, reaction of N-formylphenylglycine methyl ester (4) results in a triazoline (5) in 80% yield. ... 

Taking stereoselectivity a stage further, MoOPH has been successfully employed in the enantioselec-tive oxidation of esters bearing an enolate face discriminating chiral auxiliary.Thus exposure of the... 

Fig. 12. The effect of temperature on the induction period (min) for the oxidation of esters [93]. (1) Methyl propionate. (2) Methyl acetate. (3) Ethyl formate. (4) Methyl formate. (5) Methyl butyrate.

The oxidation of esters is a chain process with initiation by the reaction RH + 02 R- + HOj ... 

The rate of initiated oxidation of esters obeys the equation... 

Carbon dioxide formation accompanies the oxidation of esters. In the initiated oxidation of cyclohexanol [319,320] and cumene [320], C02 is formed from dimethyl esters of dicarboxylic acids through an intermediate, probably hydroperoxide, by... 

Hydroxy-esters. - The asymmetric oxidation of ester enolates using,... 

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