Baeyer-Villiger oxidation of cyclohexanone

The Baeyer-Villiger oxidation of cyclohexanone to form e-caprolactone (78) using peroxybenzoic acid, as indicated in equation (40), may be considered as a further type of intramolecular displacement reaction of value in seven-membered ring synthesis (49JA2571). 

Baeyer-Villiger oxidation of cyclohexanone is used for the preparation of e-... 

The Baeyer-Villiger oxidation of cyclohexanone to the seven-membered lactone used aqueous formic acid (5% water) as medium, and a 60% conversion at 88% selectivity was found [313]. 

Figure 1 Intermolecular and intramolecular 2H and, 3C isotope effects for the Baeyer-Villiger oxidation of cyclohexanone (standard deviations in parentheses).

The Baeyer-Villiger oxidation of cyclohexanone to e-caprolactone using H202 in (CF3)2CHOH proceeds via 7,8,15,16-tetraoxadispiro[5.2.5.2]hexadecane 32. The tetraoxane can be isolated and rearranges to the lactone on treatment with catalytic amounts of 4-TsOH <02 AG(E)4481>. 

Figure 2.47 Baeyer-Villiger oxidation of cyclohexanone in the presence of peroxomono-sulfate system.

Oxepan-2-one 18 (hexano-6-lactone, f caprolactone) is of commercial importance for the production of the polyester poly-s -caprolactone. It is obtained by a Baeyer-Villiger oxidation of cyclohexanone with peroxy acids ... 

The Ti-silicalite catalysed Baeyer-Villiger oxidation of cyclohexanone by H2O2 in aqueous solution promotes a high concentration of OH radicals, which accelerate the reaction and the consecutive formation of adipic acid (and of lighter diacids as well) as the kinetically preferred product. In the absence of the catalyst, the primary reaction product is e-caprolactone, which quickly undergoes consecutive transformations to form adipic acid even when a stoichiometric amount of the oxidant is used, since it is more reactive than cyclohexanone. The choice of solvent, which could act as a radical scavenger, also allows control over the reaction rates. ° ... 

The Baeyer-Villiger oxidation of cyclohexanone with aqueous hydrogen peroxide has been reported to result in a thermally activated radical leading to the formation of adipic acid. An oxidative rearrangement of 2-furylcarbamates to A-Boc-5-hydroxypyrrol-2(5//)-ones has been reported (Scheme 63). ... 

The reason that C6H5CHO (ben) is more effective than (Me)2CHCHO (iso) in the Baeyer-Villiger oxidation of cyclohexanone with O2, catalysed by meso-tetraphenyl porphyrin chloride, is that the highly reactive high-valent Fe-porphyrin species is formed in the presence of (ben) and the less reactive peroxy isobutyric acid is formed in the presence of (iso). ... 

Hawkins has used permaleic acid for the Baeyer-Villiger oxidation of cyclohexanone to obtain cyclohexanolide in a 90-100% yield. He has shown that if any free hydrogen peroxide is present, the yield could suffer... 

Being more tolerant to impurities dian aluminium alkoxides, Sn(Oct)2 is widely used for the industrial production of PCL and PLAs mainly in bulk, within batch reactors. Any discussion on die industrial production of polymers has to integrate not only the polymerisation process, but also the monomer production. eCL is prepared by the Baeyer-Villiger oxidation of cyclohexanone (Renz et al, 1999 Rocca et al, 2003), which is produced by the catalytic oxidation of cyclohexane, itself resulting from the catalytic reduction of benzene, made available from oil, a non-renewable resource (Fig. 4.8). 

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