Russian Chemical Bulletin, International Edition, Vol. 65, No. 2, pp. 464—468, February, 2016
464
Synthesis and kinetic regularities of the thermal decomposition
of new hydrotrioxides of cyclic alcohols
S. A. Grabovskiy,a L. R. Khalitova,a A. V. Fedorova,b A. N. Lobov,a L. Z. Rol´nik,b and N. N. Kabal´novaa
aInstitute of Organic Chemistry, Ufa Research Center of the Russian Academy of Sciences,
71 prosp. Oktyabrya, 450054 Ufa, Russian Federation.
Fax: +7 (347) 235 6066. Eꢀmail: stas_g@anrb.ru
bUfa State Oil Technical University,
1 ul. Kosmonavtov, 450062 Ufa, Russian Federation.
Fax: +7 (347) 243 1419
Cyclic hydrotrioxides were synthesized by lowꢀtemperature (–78 °С) ozonolysis of a series
of cyclic alcohols and identified using 1H NMR spectra. The kinetic regularities of the thermal
decomposition of the synthesized hydrotrioxides were studied. The experimental proof of the
induced decomposition of alcohol hydrotrioxides was obtained for the first time using
cyclohexanol hydrotrioxide as an example. The influence of cyclic substituents on the thermal
stability of the hydrotrioxides is shown.
Key words: ozonation, hydrotrioxides, thermolysis, rate constants.
(2), cyclobutanol (3), cyclopentanol (4), cyclohexanol (5),
cycloheptanol (6), cyclooctanol (7), 2ꢀisopropylꢀ5ꢀ
methylcyclohexanol (8), 1,7,7ꢀtrimethylbicyclo[2.2.1]heptanꢀ2ꢀ
ol (9), 1,3,3ꢀtrimethylbicyclo[2.2.1]heptanꢀ2ꢀol (10), heptanꢀ
4ꢀol (11), 2ꢀmethylpropanꢀ1ꢀol (12), and propanꢀ2ꢀol (13).
Compounds 1 (98%, Aldrich), 5 (98%, Aldrich), 8, 12, and
13 were purified by distillation under atmospheric pressure.
Alcohols 2—4, 6, 7, and 9—11 were synthesized by the reduction
of the corresponding ketones with lithium aluminum hydride in
ButOMe using a standard procedure5 in isolated yields of 85—
60%. According to the GLC data, the purity of the synthesized
alcohols was >98%. tertꢀButyl methyl ether (98%, Aldrich) was
purified by distillation under atmospheric pressure and kept over
molecular sieves 4 Å. Ozone was obtained in an ozonator of the
standard structure.6 Triphenylphosphine (Ph3Р) was
recrystallized from ethanol and dried in vacuo. Freonꢀ11 (СFCl3)
was saturated with ozone to the stable blue color and kept for 2 h,
then ozone was blown out with an inert gas, and CFCl3 was
treated with sodium carbonate, dried with anhydrous MgSO4,
and distilled.
Hydrotrioxides were identified by 1Н NMR spectroscopy on
a Bruker AM 500 spectrometer with a working frequency of
500.13 MHz (Me4Si as standard, solvent tolueneꢀd8 (degree of
deuteration 99.6%, Aldrich)). The products were analyzed on
CHROM 5 (column: l = 5 m, diameter of the column 3 mm,
stationary phase SEꢀ30, range of working temperatures 50—270 °С,
helium as a carrier gas) and Hewlett Packard 5890E SERIES II
(capillary column HPꢀ5, stationary phase Crosslinked 5%
PH ME Silicon, column 30 m×0.32 mm, film thickness
0.25 μm) gas chromatographs.
Hydrotrioxides are unstable intermediates of the lowꢀ
temperature ozonolysis of saturated organic and
organoelement compounds. The study of the regularities
of their synthesis and decomposition makes it possible to
understand deeper the ozonation mechanism.
Hydroperoxides, as well as peroxides of other classes, have
a weak O—O bond and during thermolysis they tend to
homolytic cleavage to form free radicals, which can initiate
their induced consumption in the radical chain process.1
It has previously been shown2 that the fraction of the
radical reaction channel during thermal decomposition of
hydrotrioxides of various classes of organic compounds
does not exceed 10%, whereas for propanꢀ2ꢀol
hydrotrioxide it is lower than 3%. In the course of
ozonation, hydrotrioxides are accumulated along with their
consumption in the reaction with ozone also leading to
the formation of radicals.1,2 We established that for the
thermolysis of exoꢀnorborneol hydrotrioxide the yield of
singlet oxygen decreases with temperature.3 One of the
reasons for this dependence can be induced radical chain
decomposition of hydrotrioxide.4
In this work, hydrotrioxides of a series of cyclic alcohols
were synthesized for the first time, their thermal stability
was studied, and induced decomposition of cyclohexanol
hydrotrioxide was found.
Experimental
Synthesis and thermolysis of alcohol hydrotrioxides. A cooled
ozone—oxygen mixture was passed through solutions of alcohols
1—13 (0.15—0.54 mol L–1) in tertꢀbutyl methyl ether (the
temperature of the solutions was maintained at –78 °C). The
The following alcohols were chosen for the synthesis of
hydrotrioxides: cyclopropylmethanol (1), 1ꢀcyclopropylethanol
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 0464—0468, February, 2016.
1066ꢀ5285/16/6502ꢀ0464 © 2016 Springer Science+Business Media, Inc.