Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 2, pp. 176−181.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © V.A. Kuznetsov, M.G. Pervova, Yu.G. Yatluk, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 2, pp. 191−196.
AND INDUSTRIAL INORGANIC CHEMISTRY
Synthesis of ε-Caprolactone
with Stable Hydrogen Peroxide Adducts
V. A. Kuznetsov, M. G. Pervova, and Yu. G. Yatluk
Postovsky Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia
Received September 10, 2012
Abstract—Oxidation of cyclohexanone to ε-caprolactone with stable industrially manufactured hydrogen peroxide
derivatives: adduct with urea (urea hydrogen peroxide), sodium perborate, sodium percarbonate (Persol), mag-
nesium monoperphthalate (Dismozon) was studied. Oxidation with urea hydrogen peroxide is the most efﬁ cient
in hexaﬂ uoroisopropanol in the case of preliminary removal of urea in the form of an oxalate. Oxidation with
sodium perborate and percarbonate provides high yields in triﬂ uoroacetic acid. The lowest cost process consists
in interaction with sodium monoperphthalate (Persol and phthalic anhydride) in an aqueous medium.
ε-Caprolactone is a valuable monomer used to obtain
biodegradable polymers for household and medicinal
purposes. The manufactured amount of ε-caprolactone
and its homo- and copolymers is steadily increasing in
most of advanced countries. The demand for polymers
of this kind also grows in our country primarily due
to the replacement of the conventional surgical suture
materials (silk, catgut) with synthetic bioabsorbable
materials based on polyoxyalkanoates.
The conventional way to synthesize ε-caprolactone
is via oxidation of cyclohexanone with peroxy acids or
Caro’s acid by the Bayer–Villiger reaction . Also,
various organic peroxy acids and catalytic systems
with hydrogen peroxide have been suggested .
These processes, as a rule, require a high concentration
of hydrogen peroxide whose solutions are not only
unstable, but also dangerously explosive.
Use of H
adducts is preferable owing to their
higher stability and safety in transportation and storage.
Adducts of this kind are widely used as bleaching and
disinfectant agents and can serve as convenient and
commercially available oxidants.
For example, it is known that oxidation of cyclo-
hexanone with urea hydrogen peroxide [UHP, H
] well occurs under heating in hexaﬂ uoroiso-
propanol in the presence of p-toluenesulfonyl acid.
In this case, the yield of ε-caprolactone is 71% [3, 4].
Oxidation with sodium perborate in acetic acid must
give ε-caprolactone in 91% yield . Sodium percar-
bonate can also be used as oxidizing agent in an acid
medium. In this case, the yield of ε-caprolactone in tri-
ﬂ uoroacetic acid is in the range from 66%  to 81%
. Magnesium monoperphthalate is used to oxidize
cyclohexanone in various media. For example, the yield
of ε-caprolactone in DMFA is 66% , high yields of
lactones (80–99%) are obtained in a water–methanol
solution [9, 10].
In the present study, we compare stable industrially
manufactured hydrogen peroxide adducts as
cyclohexanone oxidants by the Bayer–Villiger reaction
and optimize the conditions of oxidation reactions to
UHP manufactured by Lugansky chemical-pharma-
ceutical factory was used without additional puriﬁ ca-
tion. Sodium perborate (NaBO
O) of special-