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Pleas Ge rd eo e nn o Ct ah de j mu si ts mt r ya rgins
DOI: 10.1039/C5GC01688F
Journal Name
COMMUNICATION
formation. Alternatively a proton transfer can occur leading to
secondary alkoxide anion. The intramolecular attack of the
secondary alkoxide on a carbonyl group leads to the formation
of the five-membered cyclic carbonate. Since all the reactions
in the system are reversible eventually the most
thermodynamically stable product, the five-membered cyclic
carbonate is formed exclusively. The similar phenomenon was
3
6
observed by Rokicki et al.
hydroxymethyl-1,3-dioxolan-2-one.
It should be noted here, that under appropriate conditions
the monomer is stable and does not undergo isomerization.
The solution of in ethyl acetate has been kept at -5 °C for 3
during synthesis of 4-
Scheme 3 The possible mechanizm of isomerization of 5-hydroxy-1,3-dioxane-2-
one (2) into 4-hydroxymethyl-1,3-dioxolan-2-one in presence of a base.
2
–1
2
and six-membered cyclic carbonate (1741 cm ) carbonyl
groups, while the absorption band of five-membered cyclic
years without signs of isomerization.
-1
-
In the end it should be stated, that six-membered cyclic
carbonate having alkoxy or alkyl substituents in the 5 position
easily undergo polymerization leading to linear or
carbonate carbonyl (1785 cm ) and hydroxyl groups (3500 cm
1
1
)
are not present. The H NMR also confirmed the structure of
(see Fig. 2S in the Electronical Supplematry Materials file).
3
8
, 37
hyperbranched polycarbonates.
Reactivity of 2 and 3
In contrast to five-membered cyclic carbonates which are
thermodynamically stable, six-membered cyclic carbonates
Conclusions
This study, presents for the first time the synthesis of one
of the last unknown simple glycerol derivatives, six-
polymerize easily. 5-hydroxy-1,3-dioxan-2-one
classified as a latent branching AB monomer with two types
hydroxyl and carbonate) of reactive groups. In theory the
(2) can be
a
2
membered cyclic glycerol carbonate, 5-hydroxy-1,3-dioxan-2-
one. Obtained product was comprehensively characterized.
(
polymerization of
2
should lead to a hyperbranched aliphatic
was performed
at 80 °C with 1%mol of 1,8-diazabicyclo[5.4.0]undec-7-ene
The reactivity of
2
and its biscyclic ester derivative
or
3
3
was
was
polycarbonate. The anionic polymerization of
2
investigated. No ring opening polymerization of
2
1
observed, instead an isomerization to an appropriate five-
membered cyclic carbonates occured. Furthermore, the
(
DBU) as a catalyst. The analysis of H NMR and FT-IR spectra
during the process showed that instead of
homopolymerization, the isomerization of took place. The
only product showed to be 4-hydroxymethyl-1,3-dioxolan-2-
protection of the hydroxyl group
2 with an ester type
2
substituent does not protect against isomerisation.
3
6
1
one. The progress of isomerization monitored by H NMR is
shown in Fig. 5. The spectrum of gradually changed to a
2
Acknowledgements
characteristic set of signals consisting of a multiplet of methine
proton at approx. 4.75 ppm and four sets of pairs of dublets
for protons of endo- and exocyclic methylene groups. The
process proceeded rapidly within 10 min.
Prof. G. Rokicki is kindly acknowledged for many helpful
remarks during preparation of this work.
Similarly, attempts of polymerization of
3 were performed
Notes and references
using 1%mol DBU as a catalyst. The progress of the reaction
1
was monitored by means of H NMR and FT-IR. The changes in 1.
X. Sheng, G. Ren, Y. Qin, X. Chen, X. Wang and F. Wang,
Green Chemistry, 2015, 17, 373-379.
1
the H NMR spectrum were analogous to those shown in Fig. 5.
2
.
J. Feng, R.-X. Zhuo and X.-Z. Zhang, Progress in Polymer
Science, 2012, 37, 211-236.
S. Tempelaar, L. Mespouille, O. Coulembier, P. Dubois and
A. P. Dove, Chemical Society Reviews, 2013, 42, 1312-
The formation of five-membered cyclic carbonate species was
observed. (see Fig. 3S in Electronical Suplementary Materials
file). Furthermore, the FT-IR spectrum (Fig. 6) showed
appearance of the characteristic absorption band of the
3
4
5
.
.
.
1
336.
–
1
carbonyl group of five-membered carbonate ring at 1800 cm .
Additionally, the disappearance of characteristic
absorption bands corresponding to six-membered cyclic
D. P. Sanders, K. Fukushima, D. J. Coady, A. Nelson, M.
Fujiwara, M. Yasumoto and J. L. Hedrick, Journal of the
American Chemical Society, 2010, 132, 14724-14726.
J. M. Chan, H. Sardon, A. C. Engler, J. M. García and J. L.
Hedrick, ACS Macro Letters, 2013, 2, 860-864.
–1
1
carbonate at 765, and 1732 cm were observed. The H NMR
spectrum of the final product bis[(2-oxo-1,3-dioxolan-4-
) is given in Electronical Suplementary 6.
yl)methyl] sebacate (
Materials file.
4
Y. E. Aguirre-Chagala, J. L. Santos, B. A. Aguilar-Castillo
and M. Herrera-Alonso, ACS Macro Letters, 2014, 3, 353-
3
58.
The possible mechanism of isomerization of
2
is presented
7
8
.
.
W. Chen, H. Yang, R. Wang, R. Cheng, F. Meng, W. Wei
and Z. Zhong, Macromolecules, 2010, 43, 201-207.
P. G. Parzuchowski, M. Jaroch, M. Tryznowski and G.
Rokicki, Macromolecules, 2008, 41, 3859-3865.
in Scheme 3. In the first reaction step, opening of the six-
membered carbonate ring leads to formation of a primary
alkoxide anion. It can intermolecularly attack the carbonyl
group in the next monomer molecule leading to a dimer
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