Synthesis and X-ray structural analysis of an acyclic bifunctional vicinal triketone, its hydrate, and its ethanol-adduct

Article abstract of DOI:10.1016/j.tet.2013.03.065

We have synthesized and fully characterized an acyclic bifunctional vicinal tricarbonyl compound, its hydrate, and its ethanol-adduct, which could be converted to one another by utilizing the reversible addition-elimination of water or ethanol. X-ray sing

Full text of DOI:10.1016/j.tet.2013.03.065

Tetrahedron 69 (2013) 4076e4080
Contents lists available at SciVerse ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis and X-ray structural analysis of an acyclic bifunctional
vicinal triketone, its hydrate, and its ethanol-adduct
,
Morio Yonekawa a b, Yoshio Furusho a, Yoshihisa Sei c, Toshikazu Takata b,
,
Takeshi Endo a
*
a Molecular Engineering Institute, Kinki University, 11-6 Kayanomori, Iizuka, Fukuoka 820-8555, Japan
b Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 1-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
c Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
We have synthesized and fully characterized an acyclic bifunctional vicinal tricarbonyl compound, its
hydrate, and its ethanol-adduct, which could be converted to one another by utilizing the reversible
additioneelimination of water or ethanol. X-ray single crystal study revealed that the bistriketone ex-
panded and contracted by 10e30% in length during the interconversion.
Received 21 February 2013
Received in revised form 15 March 2013
Accepted 16 March 2013
Available online 22 March 2013
Ó 2013 Elsevier Ltd. All rights reserved.
Keywords:
Vicinal tricarbonyl
gem-Diol
Hemiketal
Reversibility
1. Introduction
vicinal tricarbonyl structures in the side chains and detailed in-
vestigation of reversible additioneelimination behavior of water or
Vicinal tricarbonyl compounds, such as alloxan, 1,2,3-
indanetrione, dehydroascorbic acid, and diphenylpropanetrione
(DPPT,1, Scheme 1a), are known to have a highlyelectrophilic nature
due to the three contiguous carbonyl groups, which are activated by
the adjacent two carbonyl groups.1,2 Consequently, they are highly
reactive toward various nucleophiles, such as water and alcohols, to
afford the corresponding hydrate or alcohol-adduct. These
covalently-bonded water or alcohols can be eliminated to give pure
free tricarbonyls by heating under vacuum,3,4 sublimation,4,5 dis-
tillation,6e8 crystallization,7 azeotropic removal,8 and utilization of
molecular sieves or P2O5.5,8,9 Of particular interest is that the hy-
dration and alcohol-addition processes are reversible10 and are ac-
companied by disappearance and appearance of the distinctive
yelloweorange color due to the collapse and recovery of the con-
tiguous three carbonyl groups, respectively, hence being detectable
by the naked eye.1
alcohols to the vicinal tricarbonyl moiety of the polymer.11e13
Moreover, we have successfully constructed the reversible cross-
linking and de-cross-linking system that can be controllable at
ambient conditions, utilizing the direct waterealcohol exchange
reaction on the vicinal tricarbonyl groups.14
Several bifunctional vicinal polycarbonyl compounds have been
reported to date. For example, Wasserman and Baldino synthesized
bifunctional a,b-diketoesters tethered by phenylene, naphthylene,
and decamethylene linkers and found that these compounds acted
as dielectrophiles toward the amino groups of DNA bases, effec-
tively cross-linked the DNA strands.15 Gleiter and Schang synthe-
sized two bifunctional cyclic vicinal triketones (1,2,3,5,6,7-s-
hydrindacenehexone, and 1,2,3,6,7,8-pyrenehexone), which formed
1:1 donoreacceptor complexes with pyrene.16 The same group also
reported the synthesis and structure of a cyclic bifunctional vicinal
tetraketone, and disclosed the presence of some intra-annular in-
teractions in the solid state by X-ray single crystal structure anal-
ysis.17 Thus, bifunctional vicinal polycarbonyl compounds are of
interest from a viewpoint of not only their molecular structures but
also their chemical properties that could lead to the application to
cross-linking agents. Another important feature of the vicinal tri-
carbonyl compounds is their relatively large structural changes
accompanied by the addition of water and alcohols, which could be
applied to polymer systems to create new stimuli-responsive
We have started our studies to develop new polymer materials
based on the vicinal tricarbonyl structures, motivated by the
characteristic features of vicinal tricarbonyl compounds. Recently,
we reported design and synthesis of a polystyrene bearing acyclic
* Corresponding author. Tel.: þ81 948 22 7210; fax: þ81 948 21 9132; e-mail
addresses: tendo@moleng.fuk.kindai.ac.jp, tendo@me-jsr.fuk.kindai.ac.jp (T. Endo).
0040-4020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2013.03.065

M. Yonekawa et al. / Tetrahedron 69 (2013) 4076e4080
4077
Scheme 1. (a) Structure of DPPT 1, (b) synthesis of the bistriketone 3, its hydrate 4, and its ethanol-adduct 5.
materials or supramolecular systems such as molecular machines
or molecular muscles.18 Investigation on the structural changes
of bifunctional vicinal tricarbonyl compounds is an important,
preliminary step toward future design and synthesis of such
stimuli-responsive supramolecular systems consisting of vicinal
tricarbonyl polymers. Herein, we report the facile synthesis,
structures, and chemical properties of an acyclic bifunctional vici-
nal tricarbonyl compound (bistriketone, 3), its hydrate 4, and its
ethanol-adduct 5 together with the drastic structural changes
accompanying their reversible interconversion.
bistriketone 3 in CDCl3, whereas an additional singlet peak due to
the gem-diol protons was observed at 7.88 ppm for hydrate 4 in
DMSO-d6 (Fig. S1, Supplementary data (SD)). Similarly, the signals
assignable to the hemiketal hydroxyl protons along with the ethoxy
groups were observed in addition to those due to the aromatic
protons in the 1H NMR spectrum of 5 in CDCl3. In the 13C NMR
spectrum of bistriketone 3, the three sequential carbonyl carbons
gave three peaks at 191.9, 191.8, and 187.2 ppm (Fig. S2, SD). On the
other hand, only two carbonyl signals along with one signal for
the quaternary carbon for the gem-diol or hemiketal signal were
observed in the 13C NMR spectra of 4 or 5, respectively.
The IR and UV/vis spectra of 3 showed characteristic absorptions
originating from its vicinal tricarbonyl structure. As for IR, the
bistriketone 3 exhibited the diagnostic absorption of the stretching
vibration of its vicinal tricarbonyl groups at 1723 cmꢁ1, a close value
to that of the monofunctional triketone DPPT 1 (1715 cmꢁ1, Fig. S3,
SD). On the other hand, the hydrate 4 and the ethanol-adduct 5
offered absorption peaks at around 3400 cmꢁ1 due to the OeH
groups of the gem-diol or hemiketal structures instead of the tri-
carbonyl absorption at around 1720 cmꢁ1. UV/vis absorption
spectra of 3, 4, and 5 together with that of DPPT 1 were shown in
Fig. 1. A solution of the bistriketone 3 in dry 1,4-dioxane exhibited
2. Results and discussion
The bifunctional vicinal tricarbonyl compound 3 (bistriketone),
its hydrate 4, and its ethanol-adduct 5 were synthesized according
to Scheme 1b. Treatment of dimethyl terephthalate and acetophe-
none with NaH in THF at 50 ꢀC afforded the bifunctional 1,3-
diketone 2. Oxidation of the two 1,3-diketone moieties of 2 by N-
bromosuccinimide (NBS) in DMSO at 80 ꢀC for 1 day resulted in the
formation of the corresponding bistriketone 3, confirmed in situ
with the orange coloration of the reaction mixture originating from
the vicinal tricarbonyl structures. Since the tricarbonyl compound 3
is labile to hydration by moisture in solvents or air during isolation
processes, we isolated its hydrate form 4 instead of 3; on addition of
an excess of water to the reaction mixture, the color of the solution
immediately turned light yellow indicating hydration of 3. After 1 h,
a large amount of water was added to the solution and the resulting
suspension was filtered. The residue was washed with water and
chloroform to obtain bis(gem-diol) 4 as a colorless solid. Heating 4
at 100 ꢀC in vacuo for 4 h resulted in quantitative generation of
orange-colored bistriketone 3. Conversely, hydration of 3 pro-
ceeded smoothly upon treatment with water/acetone (1/9, v/v) for
1 h and 4 was quantitatively obtained after evaporation of the
volatile components. The ethanol-adduct 5 was obtained by
treatment of 3 with hot ethanol; when a suspension of bistriketone
3 in ethanol was heated at 70 ꢀC, it became homogeneous. The
solution was then cooled to rt, to form a white precipitate, which
was collected by suction filtration and washed with n-hexane to
obtain the ethanol-adduct 5. The white microcrystalline solid of 5
contained ethanol molecules included in the crystalline lattice,
which were hardly removed by simply heating in vacuo. The
ethanol-containing solid of 5 was subjected to recrystallization
from ethyl acetate to give pure 5 as a white microcrystalline solid
that did not contain any solvent molecules. Similarly to the hydrate
4, elimination of the ethanol from 5 proceeded by heating; 3 was
regenerated quantitatively by heating 5 at 120 ꢀC in vacuo for 1 h.
The structures of bistriketone 3, its hydrate 4, and its ethanol-
adduct 5 were confirmed unambiguously by NMR, IR, and UV/vis
spectroscopies. Four peaks assignable to the phenyl and p-phe-
nylene protons were observed in the 1H NMR spectrum of
an absorption in the region from 400 to 500 nm with a maximum
3
value of 128 Mꢁ1 cmꢁ1 at 456 nm arising from the carbonyl nꢁ
p*
transitions. The maximal absorption wavelength of 3 approxi-
mately coincided with that of DPPT 1 (450 nm),11 indicating clearly
that the conjugated system of the vicinal tricarbonyl structure was
not elongated. In contrast to the bistriketone 3, the hydrate 4 in 1,4-
dioxane/water (97/3, v/v) and the ethanol-adduct 5 in 1,4-dioxane/
ethanol (97/3, v/v) showed a negligible absorption in the same
region, which is attributable to the collapse of the conjugate sys-
tems consisting of the three sequential carbonyl groups as a result
of the addition of water or ethanol to the central ones.
Fig. 1. UV/vis absorption spectra of 3 in 1,4-dioxane, 4 in 1,4-dioxane/water (97/3, v/v),
and 5 in 1,4-dioxane/ethanol (97/3, v/v) along with DPPT 1 in 1,4-dioxane.

4078
M. Yonekawa et al. / Tetrahedron 69 (2013) 4076e4080
Finally, the structures of these three species were determined by
compounds (Fig. 2a).1 As a whole, the bistriketone molecule took
a rod-like structure, in which the distance between the two ter-
X-ray crystallographic analysis.19 Fig. 2 shows the ORTEP drawings
of 3, 4, and 5; single crystals of 3, 4, and 5 suitable for X-ray
analysis were grown from chloroform, acetone, and ethyl acetate,
respectively. In the crystal structure of the bistriketone 3, the
sequential three carbonyl groups adopt helical conformations with
ꢀ
minal phenyl rings was 15.49 A. The crystal structure of the hydrate
4 revealed that the two central carbon atoms (C8, C17) adopted sp3-
hybrid orbitals and the four hydroxyl groups formed intramolecular
hydrogen bonds with the neighboring carbonyl oxygen atoms
ꢀ
ꢀ
slightly shorter bond lengths (ca. 0.01 A) of the central carbonyl
(O1/O2, O3/O4, O5/O6, O7/O8) with lengths of 2.61e2.63 A
ꢀ
ꢀ
C8]O2 (1.209 A) than those of the side ones C7]O1 (1.220 A), and
(Fig. 2b). Similarly to the hydrate 4, the central carbonyl carbons
(C8) of the ethanol-adduct 5 adopted tetrahedral configurations as
a result of the addition of ethanol molecules (Fig. 2c). Intra-
molecular hydrogen bonds are also observed between the hemi-
ketal hydroxyl moieties and the neighboring carbonyl oxygen
ꢀ
C9]O3 (1.217 A), as often the case with other vicinal tricarbonyl
ꢀ
atoms of 5 (O1/O3) with a length of 2.58 A. In contrast to the rod-
like structure of 3, the molecules of 4 and 5 adopted zigzag-shaped
structures in the solid state, in which the two terminal phenyl
ꢀ
ꢀ
groups are located with distances of 10.76 A and 13.77 A, re-
spectively. It follows from the changes in distance that the bis-
triketone molecule shrinks in length by 31% and 11% upon addition
of the water and ethanol molecules, respectively.
The electrochemical properties of bistriketone 3 and its ethanol-
adduct 5 were evaluated by cyclic voltammetry (CV) analysis. The
cyclic voltammograms of 3 and 5 in CH2Cl2 containing n-Bu4NPF6
are shown in Fig. 3 along with that of DPPT 1. Whereas the
DPPT 1 showed almost reversible single-electron-transfer peak, the
bistriketone 3 exhibited quasi-reversible, two-step, and two-
electron-transfer peaks. The half-wave reduction potentials of 3
were observed at E1 ¼ꢁ0.84 V and E2 ¼ꢁ1.11 V (vs Ag/Agþ),
1=2
1=2
which were presumably attributed to the formation of anionic
radical and dianion with p-quinodimethane structure,20 re-
spectively. The E1
of 3 was less negative than E1/2 of DPPT 1
1=2
(ꢁ1.06 V vs Ag/Agþ) because of the electron-withdrawing tri-
carbonyl moiety on the other side of 3. The decrease in the current
intensity of the oxidation peak indicated that the anionic species
generated from 3 was less stable than that of 1. In contrast to these
triketones, ethanol-adduct 5 exhibited a completely irreversible
reduction peak at E1/2¼ꢁ1.12 V (vs Ag/Agþ).
Fig. 3. Cyclic voltammograms of bistriketone 3 (red line), its ethanol-adduct 5 (green
line), and DPPT 1 (blue line) at 1.0 mM in CH2Cl2 solutions containing n-Bu4NPF6
(0.10 M). Sweep rate was 100 mV sꢁ1
.
3. Conclusion
In summary, we have synthesized and fully characterized the
acyclic bifunctional vicinal tricarbonyl compound 3, its hydrate 4,
and its ethanol-adduct 5. The bistriketone 3 was readily and
quantitatively hydrated upon treatment with water-containing
solvent. Conversely, the hydrate 3 was dehydrated quantitatively
by heating in vacuo. Similarly, the bistriketone 3 was converted to
Fig. 2. Single crystal X-ray structures of (a) 3, (b) 4, and (c) 5, top views (above) and
side views (below) along with the distances between the centroids of the terminal
phenyl rings. Thermal ellipsoids are drawn at 50% probability. Acetone molecules in
the crystal structure of 4 are omitted for clarity.

M. Yonekawa et al. / Tetrahedron 69 (2013) 4076e4080
4079
its ethanol-adduct by treatment with ethanol, from which the
bistriketone 3 was quantitatively regenerated by heating under
vacuum. As revealed by the X-ray crystallographic analysis, water
and ethanol molecules added to the central carbonyl sp2-carbon
atoms of the bistriketone 3 that changed to a tetrahedral configu-
ration, so that the hydrate 4 and the ethanol-adduct 5 adopted
a zigzag structure in contrast to the rod-shaped bistriketone 3. The
changes in the crystal structures indicated that the bistriketone 3
expanded and contracted by 10e30% in length as a result of the
addition and elimination of water and ethanol molecules. The cyclic
voltammogram of bistriketone indicated that the two vicinal tri-
carbonyl groups acted as two-electron acceptors though the gen-
erated dianion species is relatively labile when compared to its
monofunctional counterpart 1. As is evident from the bifunctional
nature of the bistriketone 3, it can be utilized as a reversible cross-
linking reagent for multifunctional alcoholic polymers such as
poly(vinyl alcohol) (PVA) or poly(2-hydroxyethyl methacrylate)
(PHEMA). Moreover, we envisage that the chemistry of the bis-
triketone investigated herein, though a little premature, would be
a first step toward a future design and synthesis of supramolecular
systems that can undergo reversible extension and contraction
motion in response to some external stimuli. These applications are
currently underway in our laboratory.
(400 MHz, CDCl3, 298 K):
d
16.84 (s, 2H, enol-OH), 8.10 (s, 4H,
AreH), 8.05e7.99 (m, 4H, AreH), 7.63e7.56 (m, 2H, AreH),
7.56e7.49 (m, 4H, AreH), 6.93 (s, 2H, enol-CH) ppm. 13C NMR
(100 MHz, CDCl3, 298 K):
133.0, 128.9, 127.5, 127.5 (18C, AreC), 93.9 (2C, eCH2e) ppm. IR
(ATR): 3048 (CeH), 1524 (C]O) cmꢁ1
d 187.2, 183.6 (4C, C]O), 138.8, 135.5,
.
4.1.2. 3,30-(1,4-Phenylene)bis(2,2-dihydroxy-1-phenylpropane-1,3-
dione) (4). 3,30-(1,4-Phenylene)bis(1-phenylpropane-1,3-dione) 2
(926 mg, 2.50 mmol) and NBS (890 mg, 5.00 mmol) were dissolved
in DMSO (25 mL). The mixture was stirred at 80 ꢀC for 24 h. After
cooling to ambient temperature, distilled water (5.0 mL) was added
to the solution and stirred for 1 h. The reaction was quenched by
the addition of a large amount of water and the resultant suspen-
sion was filtered. The collected solid was washed with water and
chloroform, and dried in vacuo to yield 4 (940 mg, 2.16 mmol, 87%)
as a white solid; mp 98 ꢀC (decomp.). 1H NMR (400 MHz, DMSO-d6,
298 K):
2H, eOH), 7.60 (t, J¼7.4 Hz, 2H, AreH), 7.47 (dd, J1¼7.8 Hz, J2¼7.6 Hz,
4H, AreH) ppm. 13C NMR (100 MHz, DMSO-d6, 298 K):
196.2,196.1
d
8.06 (s, 4H, AreH), 8.02 (d, J¼7.6 Hz, 4H, AreH), 7.88 (s,
d
(4C, C]O), 136.9, 133.8, 133.3, 130.2, 129.9, 128.7 (18C, AreC), 97.2
(2C, C(OH)2) ppm. IR (ATR): 3368 (OeH), 1679 (C]O) cmꢁ1. Anal.
Calcd for C24H18O8: C, 66.36; H, 4.18; O, 29.47. Found: C, 65.83; H,
4.12; N, 0.17.
4. Experimental section
4.1. General
4.1.3. 3,30-(1,4-Phenylene)bis(1-phenylpropane-1,2,3-trione)
(3). 3,30-(1,4-Phenylene)bis(2,2-dihydroxy-1-phenylpropane-1,3-
dione) 4 (1.53 g, 3.52 mmol) was heated at 100 ꢀC for 4 h under
reduced pressure (2 mmHg) to give 3 (1.40 g, 3.52 mmol, quant.) as
an orange solid; mp 140.0e141.0 ꢀC. 1H NMR (400 MHz, CDCl3,
Chloroform, chloroform-d (CDCl3), dimethyl sulfoxide, dimethyl
sulfoxide-d6 (DMSO-d6), and ethyl acetate were distilled over mo-
lecular sieves 4A (MS 4A). Acetone and acetophenone were distilled
over CaCl2. Ethanol was distilled over CaH2. Tetrahydrofuran (THF)
and 1,4-dioxane were distilled over sodium benzophenone ketyl.
NaH (60% in oil) (WAKO, Japan) was washed with n-hexane before
use. Diphenylpropanetrione (DPPT, 1) was synthesized according to
the literature.11 Other reagents were used as received.
298 K):
J¼7.4 Hz, 2H, AreH), 7.58 (dd, J1¼7.9 Hz, J2¼7.6 Hz, 4H, AreH) ppm.
13C NMR (100 MHz, CDCl3, 298 K):
191.9, 191.8, 187.2 (6C, C]O),
d
8.25 (s, 4H, AreH), 8.02 (d, J¼6.8 Hz, 4H, AreH), 7.74 (t,
d
136.6, 135.8, 132.0, 130.6, 130.4, 129.3 (18C, AreC) ppm. IR (ATR):
1723 (central C]O), 1675 (side C]O) cmꢁ1. Anal. Calcd for
C24H14O6: C, 72.36; H, 3.54; O, 24.10. Found: C, 71.80; H, 3.38; N,
0.00.
1H and 13C NMR spectra were measured on a JEOL JNM-ECS 400
spectrometer at a resonance frequency of 400 and 100 MHz, re-
spectively, with tetramethylsilane (TMS) as the internal standard.
4.1.4. Hydration of 3. To a solution of 3 (267 mg, 0.670 mmol) in
acetone (6.3 mL), water (0.70 mL) was added and the solution was
stirred at ambient temperature. After 1 h, the solvent of the
resulting suspension was removed under reduced pressure to give
4 (291 mg, 0.670 mmol, quant.) as a white solid.
NMR chemical shifts were reported in delta unit (d). IR spectra were
recorded on a Thermo Scientific Nicolet iS10 spectrometer. UV/vis
spectra were measured with a JASCO V-570 spectrophotometer in
a 1-cm quartz cell. Melting points were measured on a Stuart Sci-
entific SMP3 apparatus. Elemental analyses were carried out using
a LECO CHNS-932. The single crystal X-ray data were collected on
4.1.5. 3,30-(1,4-Phenylene)bis(2-ethoxy-2-hydroxy-1-phenylpropane-
a Bruker Smart Apex CCD-based X-ray diffractometer with Mo-K
a
1,3-dione)
(5). 3,30-(1,4-Phenylene)bis(1-phenylpropane-1,2,3-
ꢀ
radiation (
l
¼0.71073 A). Cyclic voltammograms were recorded at
trione) 3 (851 mg, 2.14 mmol) was suspended in ethanol (4.0 mL)
at ambient temperature and then the suspension was heated to
70 ꢀC. After 20 min, the resulting solution was cooled to ambient
temperature and allowed to stand for 1 h. The resulting pre-
cipitation was filtered, washed with n-hexane, and dried in vacuo.
The crude product was recrystallized in dry EtOAc to afford 5
(798 mg, 1.63 mmol, 76%) as colorless blocks; mp 103 ꢀC (decomp.).
a scan rate of 100 mV/s on an ALS Electrochemical Analyzer Model
612D using a glassy carbon working, a Pt counter, and an Ag/Agþ
reference electrodes, and Bu4NPF6 (0.1 M) was used as supporting
electrolyte for CH2Cl2 solutions.
4.1.1. 3,30-(1,4-Phenylene)bis(1-phenylpropane-1,3-dione)
(2). To
a suspension of NaH (4.80 g, 200 mmol) in dry THF (100 mL), di-
methyl terephthalate (9.71 g, 50.0 mmol) and acetophenone
(11.7 mL, 100 mmol) were added and stirred for 20 min at ambient
temperature under Ar atmosphere. Then the mixture was stirred at
50 ꢀC for 33 h. After cooling the mixture to ambient temperature,
the reaction was quenched by the addition of aqueous HCl (2 M,
100 mL) and a large amount of water. The resultant suspension was
filtered and the collected solid was washed with water and chlo-
roform, and dried in vacuo to yield 2. The combined filtrate was
extracted with chloroform and washed with water, dried over
MgSO4, filtered, and concentrated in vacuo. The crude material was
recrystallized from toluene to yield 2 (14.0 g, 37.8 mmol, 76%) as
a light yellow solid; mp 175.9e176.7 ꢀC (lit. 176e177 ꢀC).21 1H NMR
1H NMR (400 MHz, CDCl3, 298 K):
d 8.25 (s, 4H, AreH), 8.18 (d,
J¼7.4 Hz, 4H, AreH), 7.61 (t, J¼7.4 Hz, 2H, AreH), 7.46 (dd, J1¼7.8 Hz,
J2¼7.6 Hz, 4H, AreH), 5.91 (s, 2H, eOH), 3.69e3.48 (m, 4H,
eOCH2e), 1.20 (t, J¼6.9 Hz, 6H, eCH3) ppm. 13C NMR (100 MHz,
CDCl3, 298 K):
d 195.7, 195.3 (4C, C]O), 136.7, 134.5, 132.5, 130.7,
130.5, 128.7 (18C, AreC), 99.6 (2C, C(OH)(OR)), 59.2 (2C, eOCH2e),
15.5 (2C, eOCH3) ppm. IR (ATR): 3419 (OeH), 2978 (CeH), 1694,
1674 (C]O) cmꢁ1. Anal. Calcd for C28H26O8: C, 68.56; H, 5.34; O,
26.09. Found: C, 67.99; H, 5.12; N, 0.00.
4.1.6. Ethanol-elimination
from
5. 3,30-(1,4-Phenylene)bis(2-
ethoxy-2-hydroxy-1-phenylpropane-1,3-dione) (5) (123 mg,
0.250 mmol) was heated at 120 ꢀC for 1 h under reduced pressure

4080
M. Yonekawa et al. / Tetrahedron 69 (2013) 4076e4080
11. (a) Dei, T.; Morino, K.; Sudo, A.; Endo, T. J. Polym. Sci., Part A: Polym. Chem. 2011,
49, 2245e2251; (b) Dei, T.; Morino, K.; Sudo, A.; Endo, T. J. Polym. Sci., Part A:
Polym. Chem. 2012, 50, 2619e2625.
(2 mmHg) to give 3 (100 mg, 0.250 mmol, quant.) as an orange
solid.
12. Morino, K.; Sudo, A.; Endo, T. Macromolecules 2012, 45, 4494e4499.
13. For a polymer bearing cyclic tricarbonyl moiety, see: Endo, T.; Fujiwara, E.;
Okawara, M. J. Polym. Sci. Polym. Chem. Ed. 1981, 19, 1091e1099.
Acknowledgements
14. Yonekawa, M.; Furusho, Y.; Endo, T. Macromolecules 2012, 45, 6640e6647.
15. Wasserman, H. H.; Baldino, C. M. Bioorg. Med. Chem. Lett. 1995, 5, 3033e3038.
16. Gleiter, R.; Schang, P. Angew. Chem., Int. Ed. Engl. 1980, 19, 715e716.
17. Peter, M.; Gleiter, R.; Rominger, F.; Oeser, T. Eur. J. Org. Chem. 2004, 3212e3220.
18. For examples of organic molecules that undergo muscle-like extension-con-
traction motion, see: (a) Bell, T. W.; Jousselin, H. Nature 1994, 367, 441e444; (b)
This work was supported by Grant-in-Aid for Scientific Research
(B) (21350068) from the Japan Society for the Promotion of Science
(JSPS) and Japan and JSR Corporation.
Supplementary data
ꢁ
Jimenez, M. C.; Dietrich-Buchecker, C.; Sauvage, J.-P. Angew. Chem., Int. Ed. 2000,
39, 3284e3287; (c) Berni, E.; Kauffmann, B.; Bao, C.; Lefeuvre, J.; Bassani, D. M.;
Huc, I. Chem.dEur. J. 2007, 13, 8463e8469; (d) Fang, L.; Hmadeh, M.; Wu, J.;
Olson, M. A.; Spruell, J. M.; Trabolsi, A.; Yang, Y.-W.; Elhabiri, M.; Albrecht-Gary,
A.-M.; Stoddart, J. F. J. Am. Chem. Soc. 2009, 131, 7126e7134; (e) Miwa, K.;
Furusho, Y.; Yashima, E. Nat. Chem. 2010, 2, 444e449.
Detailed X-ray crystal data of 3, 4, and 5, 1H NMR, 13C NMR, and
FT-IR spectra. The supplementary data can be found in the online
version, at http://dx.doi.org/10.1016/j.tet.2013.03.065.
19. Crystal data for 3: C24H14O6: FW¼398.35, monoclinic, space group P21/c, a¼11.
3
ꢀ
ꢀ
ꢀ
ꢀ
301 (3) A, b¼5.8285 (15) A, c¼14.258 (4) A, ¼108.868 (3), V¼888.7 (4) A , Z¼2,
b
References and notes
Dcalcd¼1.489, 3846 reflections measured, 1563 unique reflections, 1302 obser-
vations (I>2.0 (I)), Rw¼0.0888 (I>2.0 (I)). CCDC 917094.
(I)), R¼0.0330 (I>2.0
Crystal data for 4: C27H24O9: FW¼492.46, triclinic, space group Pꢁ1, a¼9.4625
s
s
s
1. (a) Rubin, M. B.; Gleiter, R. Chem. Rev. 2000, 100, 1121e1164; (b) Rubin, M. B.
Chem. Rev. 1975, 75, 177e202.
ꢀ
ꢀ
ꢀ
ꢀ
a
(13) A, b¼11.3827 (16) A, c¼11.5726 (17) A,
¼92.198 (2),
513 (2), V¼1148.4 (3) A , Z¼2, Dcalcd¼1.424, 5521 reflections measured, 3983
unique reflections, 3230 observations (I>2.0 (I)), Rw¼0.
(I)), R¼0.0381 (I>2.0
1037 (I>2.0
(I)). CCDC 917095, Crystal data for 5: C28H26O8: FW¼490.49, tri-
clinic, space group Pꢁ1, a¼8.337 (3) A, b¼8.518 (4) A, c¼8.983 (4) A,
b
¼110.599 (2),
g
¼98.
3
2. Wasserman, H. H.; Parr, J. Acc. Chem. Res. 2004, 37, 687e701.
3. (a) Hirama, M.; Fukazawa, Y.; Ito, S. Tetrahedron Lett. 1978, 19, 1299e1302; (b)
Moubasher, R.; Othman, A. M. J. Am. Chem. Soc. 1950, 72, 2667e2669.
4. Lepley, A. R.; Thelman, J. P. Tetrahedron 1966, 22, 101e110.
5. (a) Netto-Ferreira, J. C.; Silva, M. T.; Puget, F. P. J. Photochem. Photobiol. A: Chem.
1998, 119, 165e170; (b) Silva, M. T.; Braz-Filho, R.; Netto-Ferreira, J. C. J. Braz.
Chem. Soc. 2000, 11, 479e485.
s
s
s
ꢀ
ꢀ
ꢀ
a
¼71.791
¼80.783 (6), V¼589.2 (4) A , Z¼1, Dcalcd¼1.382, 2815 re-
flections measured, 2035 unique reflections, 1731 observations (I>2.0
(I)), R¼0.
0582 (I>2.0 (I)). CCDC 917096. For more detail on the
3
ꢀ
(5),
b
¼77.809 (5),
g
s
s
(I)), Rw¼0.1553 (I>2.0
s
data, see Supplementary data. These data can be obtained free of charge from
the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_re-
quest/cif.
6. (a) Mahran, M. R.; Abdou, W. M.; Sidky, M. M.; Wamhoff, H. Synthesis 1987, 5,
506e508; (b) Sharp, D. B.; Hoffman, H. A. J. Am. Chem. Soc. 1950, 72, 4311e4313.
7. Roberts, J. D.; Smith, D. R.; Lee, C. C. J. Am. Chem. Soc. 1951, 73, 618e625.
8. Gill, G. B.; Idris, M. S. H.; Kirollos, K. S. J. Chem. Soc., Perkin Trans. 1 1992,
2355e2365.
20. Campbell, J. A.; Koch, R. W.; Hay, J. V.; Ogliaruso, M. A.; Wolfe, J. F. J. Org. Chem.
1974, 39, 146e152.
21. Martin, D. F.; Shamma, M.; Fernelius, W. C. J. Am. Chem. Soc. 1958, 80,
€
9. Schonberg, A.; Singer, E. Chem. Ber. 1970, 103, 3871e3884.
4891e4895.
10. Endo, T.; Okawara, M. Bull. Chem. Soc. Jpn. 1979, 52, 2733e2734.