ISSN 1070-3632, Russian Journal of General Chemistry, 2019, Vol. 89, No. 2, pp. 199–203. © Pleiades Publishing, Ltd., 2019.
Russian Text © Sh.Yu. Khazhiev, M.A. Khusainov, R.A. Khalikov, T.V. Tyumkina, E.S. Meshcheryakova, L.M. Khalilov, V.V. Kuznetsov, 2019, published in
Zhurnal Obshchei Khimii, 2019, Vol. 89, No. 2, pp. 197–201.
Structure and Conformational Analysis
of 5,5-Bis(bromomethyl)-2-methyl-2-phenyl-1,3-dioxane
Sh. Yu. Khazhieva, M. A. Khusainova, R. A. Khalikovb, T. V. Tyumkinac,
E. S. Meshcheryakovac, L. M. Khalilovc, and V. V. Kuznetsova,d*
a Ufa State Petroleum Technological University, Ufa, Russia
*e-mail: kuzmaggy@mail.ru
b Bashkirian State Medical University, Ufa, Russia
c Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, Ufa, Russia
d Ufa State Aviation Technical University, ul. K. Marksa 12, Ufa, 450008 Russia
Received July 26, 2018; revised July 26, 2018; accepted August 2, 2018
Abstract—The structure of 5,5-bis(bromomethyl)-2-methyl-2-phenyl-1,3-dioxane 1 has been studied by means
1
of Н and 13С NMR spectroscopy as well as X-ray diffraction analysis. The molecules of compound 1 exist in
the chair conformation with the axially oriented phenyl group. The computer simulation using DFT
approximation at the PBE/3ξ level has revealed the route of interconversion of the ring and the optimal
conformation of the phenyl group corresponding to the data of X-ray diffraction analysis.
Keywords: 1,3-dioxane, 5,5-bis(halomethyl)-1,3-dioxanes, X-ray diffraction analysis, conformers, computer
simulation
DOI: 10.1134/S1070363219020051
Substituted 1,3-dioxanes are interesting due to
special structural features and are widely applied as
synthons in fine organic synthesis [2–4]. For example,
5,5-bis(halomethyl)-1,3-dioxanes can be easily con-
verted into the mono- and diiodo-derivatives; the
process proceeds stereoselectively, predominantly at
the equatorial chloromethyl substituent [5].
The hitherto unknown 5,5-bis(bromomethyl)-2-methyl-
2-phenyl-1,3-dioxane was synthesized via the con-
densation of 2,2-bis(bromomethyl)-1,3-propanediol
with acetophenone (Scheme 1).
The results of X-ray diffraction investigation of the
obtained ketal are summarized in Tables 1 and 2. The
structure of the molecule of 5,5-bis(bromomethyl)-2-
methyl-2-phenyl-1,3-dioxane corresponded to the
chair conformation with the axial phenyl group (Cа,
see figure). The planes of the aromatic ring and the
О1–O5–С3–C14 fragment were practically orthogonal.
For the heteroatomic part of the heterocyclic ring, the
The conformational behavior of formals of 5,5-bis-
(halomethyl)-1,3-dioxanes at room temperature is
characterized by fast interconversion of the ring (at the
NMR timescale) [6]. On the contrary, the molecules of
2-substituted analogs exist predominantly in the chair
conformation with equatorial orientation of the
substituent at the С2 atom (Cе) [7, 8]. However,
conformational behavior of the ketals of the same
series has been scarcely studied. To fill in the gap, this
study was devoted to investigation of the structure and
conformational transformations of 5,5-bis(bromo-
Scheme 1.
C6H5
H3C
BrH2C
BrH2C
OH
+
C=O
OH
1
methyl)-2-methyl-2-phenyl-1,3-dioxane using H and
13С NMR spectroscopy, X-ray diffraction analysis, and
DFT simulation using the PBE/3ζ method imple-
mented in PRIRODA software package [9].
BrH2C
BrH2C
O C6H5
O CH3
H+
−H2O
199