Oxidation of cycloalkanones with hydrogen peroxide: an alternative route to the Baeyer-Villiger reaction. Synthesis of dicarboxylic acid esters

Article abstract of DOI:10.1016/j.tet.2008.06.027

The acid-catalyzed oxidation of cycloalkanones C₅-C₈ and C₁₂ with hydrogen peroxide in alcohols was performed, and dicarboxylic acid esters were obtained as the major products in 53-70% yields. In the first step, geminal bishydroperoxides are generated from five-to-seven-membered cyclic ketones. The Baeyer-Villiger reaction is a side process accompanied by the formation of ω-hydroxycarboxylic acid esters.

Full text of DOI:10.1016/j.tet.2008.06.027

Tetrahedron 64 (2008) 7944–7948
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Oxidation of cycloalkanones with hydrogen peroxide: an alternative route
to the Baeyer–Villiger reaction. Synthesis of dicarboxylic acid esters
*
Alexander O. Terent’ev , Maxim M. Platonov, Alexey S. Kashin, Gennady I. Nikishin
N.D. Zelinsky Institute of Organic Chemistry, Leninsky Prospect 47, Moscow 119991, Russian Federation
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 2 April 2008
Received in revised form 20 May 2008
Accepted 5 June 2008
Available online 10 June 2008
The acid-catalyzed oxidation of cycloalkanones C5–C8 and C12 with hydrogen peroxide in alcohols was
performed, and dicarboxylic acid esters were obtained as the major products in 53–70% yields. In the first
step, geminal bishydroperoxides are generated from five-to-seven-membered cyclic ketones. The
Baeyer–Villiger reaction is a side process accompanied by the formation of
esters.
u-hydroxycarboxylic acid
Ó 2008 Elsevier Ltd. All rights reserved.
Keywords:
Oxidation
Hydrogen peroxide
Cycloalkanones
Dicarboxylic acids
Bishydroperoxides
1. Introduction
In almost all studies on the Baeyer–Villiger reaction, the latter
was reported to produce hydroxy acids and lactones. The fact that
treatment of cyclic ketones with peracetic acid affords dicarboxylic
acids (containing the same number of carbon atoms) as by-prod-
ucts was documented in only one study.6 The oxidation of cyclo-
hexanone gave adipic acid in trace amounts (w1%). The oxidation of
cycloheptanone and cyclooctanone afforded pimelic and suberic
acids in 33 and 59% yields, respectively.
The problem of the development of efficient methods for the
synthesis of dicarboxylic acids and their derivatives has attracted
considerable attention for more than half a century, because these
compounds are building blocks in the production of polyamide,
polyurethane, and polyester polymers, plasticizing agents, lubri-
cants, and anticorrosive systems.
The Baeyer–Villiger reaction has been used for more than 100
years1 as an efficient procedure for the synthesis of lactones and
u
-hydroxy acids from cyclic ketones. This reaction can be performed
using numerous oxidants, such as H2SO5, H2S2O8, perbenzoic acid,
m-chloroperbenzoic acid, hydrogen peroxide, performic acid,
peracetic acid, and trifluoroacetic acid.2 The asymmetric Baeyer–
Villiger oxidation proceeds under catalytic conditions in the
presence of transition metals3 or monooxygenases.4 The commonly
accepted mechanism of acid- or base-catalyzed oxidation of ketones
suggested by Criegee5 (Scheme 1) involves the addition of peracids
to carbonyl compounds and the rearrangement of the resulting
adducts accompanied by the migration of the alkyl group.
The oxidation reactions of cyclic ketones to dicarboxylic acids
with nitric acid,7 potassium permanganate,8 and other oxidants in
the presence of catalysts containing W,9 Ce,10 Re,11 Mn,12 Cu,10a
Co,12d,e Pt,13 V,14 or Mo9b,14 were studied in detail. However, simple
methods of oxidation (without the use of additional reagents) of
cyclic ketones to dicarboxylic acids with hydrogen peroxide are
lacking.
B-
H+
H
O
R'''
O
O
O
R'''COOOH
R''
O
O
R''
R'
R'
R'
O
R''
Scheme 1. Mechanism of acid- or base-catalyzed oxidation of ketones suggested by
Criegee.
2. Results and discussion
In the present study, we report the oxidative transformation of
ketones 1a–g in the reaction with hydrogen peroxide in an alco-
holic solution, which does not require the use of percarboxylic acids
and metal-containing catalysts. This reaction affords dicarboxylic
* Corresponding author. Tel.: þ7 499 135 64 28; fax: þ7 499 135 53 28.
E-mail address: terentev@ioc.ac.ru (A.O. Terent’ev).
0040-4020/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2008.06.027

A.O. Terent’ev et al. / Tetrahedron 64 (2008) 7944–7948
7945
Table 1
acids 3a–g as the major products, which are then transformed into
the corresponding esters 4a–g (Scheme 2). The reaction gives also
Synthesis of gem-bishydroperoxides 2a,b,d,e by the reaction of ketones 1a,b,d,e with
hydrogen peroxide catalyzed by sulfuric acid in ethanol and propanola
u
-hydroxycarboxylic acid esters as by-products generated by the
O
Baeyer–Villiger oxidation of cycloalkanones. The design of the ox-
idative reaction differs from that of the Baeyer–Villiger reaction by
the order of mixing of the reagents, the temperature conditions,
and the concentration of the catalyst (strong acid).
O
O
O
Ketones 1a,b,d,e
But
1d
Earlier, we have developed a facile procedure for the synthesis
of geminal bishydroperoxides from cyclic ketones and hydrogen
peroxide in THF at 15–20 ꢀC.15 Under more severe temperature
conditions, these bishydroperoxides were demonstrated to be ox-
idized in alcohols (solvents) with hydrogen peroxide to form di-
carboxylic acid esters.16 These results led us to the idea to use
a new procedure for the oxidation of cyclic ketones to dicarboxylic
acids, that is, to perform these two reactions in one pot. The es-
sence of this reaction is that the conditions favorable for the for-
mation of geminal bishydroperoxides and for the oxidation of the
latter to dicarboxylic acids are created in the first and second steps,
respectively.
For this purpose, the reaction was performed in two steps. Ini-
tially, ketone was added with stirring to a mixture of alcohol, excess
hydrogen peroxide, and sulfuric acid at 20–25 ꢀC. The reaction
mixture was allowed to stand for 5–10 min and then heated at the
boiling point for 20–120 min. The oxidation products, dicarboxylic
acids, were isolated from the reaction mixture as esters.
To confirm the formation of geminal bishydroperoxides in the
first step of the oxidative reaction, a series of reactions with hy-
drogen peroxide were carried out in ethanol and propanol using
medium-size ring ketones, such as cyclopentanone 1a, cyclohex-
anone 1b, 4-tert-butylcyclohexanone 1d, and cycloheptanone 1e.
At 20–25 ꢀC, the reactions of the above-mentioned ketones
afforded geminal bishydroperoxides as the major products in 75–
91% yields (Table 1). Under the same conditions, the reactions of
hydrogen peroxide with cyclooctanone 1f and cyclododecanone
1g produced the corresponding geminal bishydroperoxides 2f,g in
low yields (26 and 17%, respectively). It should be emphasized
that geminal bishydroperoxides have attracted considerable at-
tention of chemists and pharmacologists because of the high
antimalarial activity discovered in these compounds and their
derivatives.17
1a
1b
1e
HOO OOH
HOO
OOH
HOO OOH
HOO OOH
gem-Bishydroperoxides
2a,b,d,e
But
2d
2a
2b
2e
Yield,b
%
75–82
78–84
88–91
81–85
a
The reaction conditions: H2O2 (5 mol per mole of ketone), the H2SO4 concen-
tration was 0.5 mol/L, the reaction time was 30 min, and the temperature was 20–
25 ꢀC. The conversion of ketones was 95–100%.
b
The yields of gem-bishydroperoxides 2a,b,d,e were determined based on the
isolated reaction product.
hydrogen peroxide. As a result dicarboxylic acids 3 are formed,
which are then transformed into the corresponding esters 4. At-
tempts to isolate intermediates failed because of the very high rate
of oxidation.
The influence of the reaction temperature and the sulfuric acid
concentration on the yield of dibutyl adipate 4b was exemplified by
the oxidation of cyclohexanone bishydroperoxide 2b with the use
of butanol as the co-solvent and an esterification reagent (Tables 2
and 3). At 50 ꢀC, a long period of time (48 h) was required to ach-
ieve the complete conversion of peroxide 2b. At 98–100 ꢀC (boiling
point of the reaction mixture), the reaction rate increases by more
than two orders of magnitude, and the yield of dibutyl adipate 4b
increases from 38 to 68%. These characteristics were achieved at an
H2SO4 concentration of 0.5 mol/L. An increase in the concentration
to 1 mol/L leads to an increase in the rate of conversion of peroxide
2b and a simultaneous decrease in the yield of 4b. A decrease in the
concentration to 0.1–0.2 mol/L results in a decrease in both the
reaction rate and the yield of the ester. The choice of butanol was
dictated by the necessity to maintain the temperature at w100 ꢀC;
the use of ethanol or propanol instead of butanol leads to a decrease
in the boiling point of the reaction mixture and, as a consequence,
to a decrease in the yields of the target diethyl and dipropyl
adipates.
The mechanism of the oxidation reaction is not quite clear.
However, the following sequence of transformations of cyclic ke-
tones into dicarboxylic acids can be suggested.
The first step involves the peroxidation of ketones 1. At heating
of the reaction mixture the acid-catalyzed transformations of
bishydroperoxides
2
occur, which include oxidation using
Baeyer-Villiger Oxidation (side reaction)
O
H2O2, H+
( )
n
R'OH
Oxidation via the stage
of bishydroperoxide formation
(main reaction)
R
1a-g
HOO OOH
( )
n
R
2a-g
O
R
n
O
O
R
O
R'OH
R'O
( )
OR'
HO
( )
n
OH
3a-g
4a-g
a: n = 1, R = H; b: n = 2, R = H; c: n = 2, R = Me;
d: n = 2, R = But; e: n =3, R = H; f: n = 4, R = H; g: n = 8, R = H
R' = Et, Pr, Bu
Scheme 2. Proposed scheme of oxidation of ketones.

7946
A.O. Terent’ev et al. / Tetrahedron 64 (2008) 7944–7948
Table 2
Table 4
Influence of the temperature on the time of complete conversion of bishydroper-
Oxidation of ketones 1a–g under optimized conditions in butanola
oxide 2b and the yield of dibutyl adipate 4ba
Ketones 1a–g
Diesters 4a–g
Yield of diester,b
% in oxidation
Temperature, ꢀC
Time of complete
conversion of 2b, h
Yield of dibutyl
50
48
70
3
98–100c
0.15
With
aqueous
H2O2
With
ethereal
H2O2
38
56
68
adipate 4b,b
%
O
a
The reaction conditions: BuOH (20 mL), H2SO4 (1.2 g, 0.5 mol/L), bishydroper-
BuO
OBu
oxide 2b (1.48 g, 10 mmol), and H2O2 (50 mmol, 37% aqueous solution).
53
61
57
65
b
O
O
The yield based on the isolated reaction product.
The boiling point of the reaction mixture.
c
4a
1a
O
O
Therefore, the best results in the key step of oxidation of cy-
clohexanone 1b, which involves the transformation of geminal
bishydroperoxide of cyclohexanone 2b into adipic acid 3b ac-
companied by its esterification to give dibutyl adipate 4b, were
obtained at an H2SO4 concentration of 0.4–0.6 mol/L and at
w98 ꢀC. Under these conditions, the virtually complete conver-
sion of 2b was achieved within 8–10 min. The yield of 4b was
68%.
To examine the possibility of the use of low-boiling alcohols
for the oxidation of ketones, several reactions were carried out in
ethanol and propanol. The influence of an excess of hydrogen
peroxide on the yield of diethyl adipate and the diethyl adipate to
ethyl 6-hydroxyhexanoate ratio was studied for the oxidation of
cyclohexanone 1b in ethanol (the solvent, which has the lowest
boiling point in the series of alcohols under study and is, con-
sequently, least favorable for the formation of diesters). It was
found that the reaction with the use of the 3-, 5-, or 10-fold
molar excess of hydrogen peroxide at the boiling point of the
reaction mixture (78–82 ꢀC) for 3 h afforded diethyl adipate in 32,
51, and 47% yields, respectively; the ratio of the yields of diethyl
adipate and ethyl 6-hydroxyhexanoate was 1.3, 1.5, and 1.6, re-
spectively. Therefore, the oxidative reaction alternative to the
Baeyer–Villiger reaction is the major process even in low-boiling
ethanol.
The oxidation of cyclic ketones can be performed in a virtually
anhydrous medium. The reaction of cyclohexanone with hydrogen
peroxide (the fivefold molar excess; a 6% ethereal solution) in
ethanol in the presence of sulfuric acid afforded diethyl adipate in
54% yield; under analogous conditions in an aqueous alcoholic
solution, the yield was 51%.
The catalytic effect of HBF4 and BF3$Et2O in the oxidation of
ketones was exemplified by the synthesis of dipropyl adipate; the
yield of the diester was 57 and 65%, respectively. The reaction with
BF3$Et2O was carried out with anhydrous hydrogen peroxide,
which allowed us to perform the oxidation of ketones under mild
conditions.
BuO
OBu
O
4b
1b
O
OBu
O
BuO
BuO
59
64
O
O
4c
1c
O
OBu
O
57
62
63
67
But
4d
But
1d
O
BuO
OBu
O
O
4e
1e
O
O
BuO
BuO
OBu
OBu
61
64
65
70
O
1f
4f
O
O
( )5
4g
O
1g
a
General reaction conditions: BuOH (20 mL), H2SO4 (1.2 or 1.1 g, 0.5 mol/L), ke-
tones 1a–g (10 mmol), H2O2 (60 mmol, 37% aqueous or 6% ethereal), 102–106 ꢀ
C
(oxidation with ethereal H2O2) and 98–100 ꢀC (oxidation with aqueous H2O2), and
the oxidation time was 20 (1a–e) and 40 (1f,g) min.
b
The yield based on the isolated reaction product.
The oxidation of ketones with the ring size of C5–C8 and C12 was
performed taking into account the results of oxidation of cyclo-
hexanone 1b and its bishydroperoxide 2b (Table 4).
3. Conclusion
It was found that the oxidation of C5–C8 and C12 cyclic ketones
with hydrogen peroxide in alcohols in the presence of sulfuric
acid can proceed not as the Baeyer–Villiger reaction but as the
formation of geminal bishydroperoxides followed by their oxida-
tion to dicarboxylic acids, which were isolated as the corre-
sponding esters. The key conditions for this transformation are as
follows: the temperature higher than 80 ꢀC, the H2SO4 concen-
tration of 0.2–1 mol/L, and the molar ketone to hydrogen peroxide
ratio of 5–10. Under these conditions, the oxidation in butanol,
which provides the maintenance of the reaction temperature
within 98–106 ꢀC, affords the corresponding dibutyl esters in 53–
70% yields.
Table 3
Influence of the H2SO4 concentration on the time of complete conversion of bis-
hydroperoxide 2b and the yield of dibutyl adipate 4ba
Concentration of H2SO4, mol/L
Time of complete
0.1
40–50
0.2
30–35
0.5b
8–10
1
5–7
conversion of bishydroperoxide 2b, min
Yield of dibutyl
50
55
68
60
adipate 4b,c
%
a
The reaction conditions: BuOH (20 mL), bishydroperoxide 2b (1.48 g, 10 mmol),
H2O2 (50 mmol, 37% aqueous solution), and temperature 98–100 ꢀC.
b
In experiments with the use of H2SO4 at a concentration of 0.4 or 0.6 mol/L, the
results remain virtually unchanged.
c
The yield based on the isolated reaction product.

A.O. Terent’ev et al. / Tetrahedron 64 (2008) 7944–7948
7947
4. Experimental section
4.1. General
amount of H2SO4 (0.24 g, 2.4 mmol; 0.48 g, 4.8 mmol; and 2.4 g,
24 mmol). Dibutyl adipate 4b was isolated as described above.
4.5. Influence of an excess of H2O2 on the ratio of the yields
of diethyl adipate and ethyl 6-hydroxyhexanoate in the
oxidation of cyclohexanone
The NMR spectra were recorded on Bruker AC-200 (200.13 MHz
for 1H), Bruker WM-250 (250.13 MHz for 1H and 62.9 MHz for 13C),
and Bruker AM-300 (75.4 MHz for 13C) spectrometers in CDCl3. The
TLC analysis was carried out on Silufol UV-254 chromatographic
plates. Flash chromatography was performed on silica gel L 40/
100 mm. The melting points were determined on a Kofler hot-stage
apparatus. Mass spectra were obtained at an ionization potential of
70 eV with a Finnigan MAT ITD-700.
Ketones were purchased from Acros. Ethanol, propanol, butanol,
CHCl3, petroleum ether (PE) (bp 40–70 ꢀC), Et2O, BF3$Et2O, H2O2
(37% aqueous solution), H2SO4 (98%), HBF4 (48%), NaHCO3, and
K2CO3 of high-purity grade were domestically produced. A solution
of H2O2 in Et2O (6 wt %) was prepared by extraction from a 37%
aqueous H2O2 solution followed by drying over MgSO4.18
The experiment was carried out by adding cyclohexanone 1b
(0.98 g, 10 mmol) with stirring to an H2O2 solution (2.76 g,
30 mmol; 4.6 g, 50 mmol; or 9.2 g, 100 mmol; aqueous solution)
and, correspondingly, to H2SO4 (1.1 g, 1.2 g, or 1.4 g, the concen-
tration in the reaction mixture was w0.5 mol/L) in ethanol (20 mL)
at 20–25 ꢀC for 5 min. The reaction mixture was kept for 5–10 min
and then heated at 78–82 ꢀC for 120 min. Then CHCl3 (100 mL) was
added, and the reaction mixture was refluxed using a Dean–Stark
trap until water was completely removed. Dry K2CO3 (5 g) was
added, and the suspension was stirred until sulfuric acid was
neutralized. The reaction products were isolated by silica gel col-
umn chromatography. The reactions with the use of the 3-, 5-, or
10-fold excess of H2O2 afforded diethyl adipate in 32, 51, and 47%
yields, respectively; the ratio of the yields of diethyl adipate and
ethyl 6-hydroxyhexanoate was 1.3, 1.5, and 1.6, respectively.
4.2. General procedure for the synthesis of gem-bishydro-
peroxides 2a,b,d–g by the reaction of ketones 1a,b,d–g
with hydrogen peroxide in ethanol or propanol catalyzed
by sulfuric acid (Table 1)
4.6. Oxidation of cyclohexanone 1b with H2SO4
and anhydrous H2O2
Hydrogen peroxide (4.6 g, 50 mmol, aqueous solution) and
H2SO4 (1.2 g, 12 mmol) were added to EtOH or PrOH (20 mL). Then
ketones 1a,b,d–g (10 mmol) were added with stirring at 20–25 ꢀC
for 5 min. The reaction mixture was stirred for 30 min. The con-
version of ketone was monitored by TLC. Then CH2Cl2 (100 mL) and
a saturated aqueous NaHCO3 solution were added to pH 7–8. The
organic layer was separated, washed with water (4ꢁ5 mL), dried
over MgSO4, and filtered. Dichloromethane was evaporated at 7–
10 mmHg, residues of alcohol and H2O2 were removed in vacuo
(0.2–1 mmHg) at room temperature for 2–3 h, and bishydroper-
oxides 2a,b,d–g were isolated. Analytically pure samples of bishy-
droperoxides were isolated by flash chromatography using PE/
Et2O¼80/20 as the eluent.
Hydrogen peroxide (28.3 g, 50 mmol, ethereal solution) and
H2SO4 (1.1 g, 11 mmol, the concentration in the reaction mixture
after the removal of diethyl ether was w0.5 mol/L) were added to
EtOH (20 mL). Diethyl ether was distilled off from the reaction
mixture under reduced pressure (w100 Torr) at room temperature.
Then cyclohexanone 1b (0.98 g, 10 mmol) was added with stirring
at 20–25 ꢀC for 5 min. The reaction mixture was heated at the
boiling point (77–80 ꢀC) until the complete conversion of 1b was
achieved (TLC monitoring, w120 min). Diethyl adipate was isolated
as described in the experiment under Table 2. The yield was 54%.
The spectral data of bishydroperoxides 2a,b,d–g are identical to
that reported in the literature.15,17c,d,19
4.7. Oxidation of cyclohexanone 1b with HBF4
The oxidation of cyclohexanone 1b with HBF4 was carried out
analogously at the boiling point in PrOH (20 mL) for 60 min with
the use of cyclohexanone 1b (0.98 g, 10 mmol), H2O2 (4.6 g,
50 mmol, aqueous solution), and HBF4 (2.36 g, 13 mmol, 48%
aqueous solution, the concentration in the reaction mixture was
w0.5 mol/L). Dipropyl adipate was isolated as described in the
experiment under Table 2. The yield was 57%.
4.3. Influence of the temperature on the time of complete
conversion of bishydroperoxide 2b and the yield of dibutyl
adipate 4b (Table 2)
Hydrogen peroxide (4.6 g, 50 mmol) and H2SO4 (1.2 g, 12 mmol,
the concentration in the reaction mixture was w0.5 mol/L) were
added to butanol (20 mL). Then bishydroperoxide 2b (1.48 g,
10 mmol) was added at room temperature. The reaction mixture
was heated at 50, 70, and 98–100 ꢀC (boiling point) until the
complete conversion of 2b was achieved (TLC monitoring). Then
CHCl3 (100 mL) was added to the reaction mixture, and the mixture
was refluxed using a Dean–Stark trap until water was completely
removed. The reaction solution was washed with saturated aque-
ous NaHCO3 to pH 7–8. The organic layer was separated, washed
with water (4ꢁ30 mL), dried over MgSO4, and filtered. The filtrate
was concentrated, and dibutyl adipate 6b was isolated by silica gel
column chromatography.
4.8. Oxidation of cyclohexanone 1b with BF3$Et2O
and anhydrous H2O2
Hydrogen peroxide (28.3 g, 50 mmol, ethereal solution) and
BF3$Et2O (2.1 g, 15 mmol) were added to PrOH (20 mL). Diethyl
ether was distilled off from the reaction mixture under reduced
pressure (w100 Torr) at room temperature. Then cyclohexanone 1b
(0.98 g, 10 mmol) was added with stirring at 15–25 ꢀC for 5 min.
The reaction mixture was heated at the boiling point (92–94 ꢀC)
until the complete conversion of 1b was achieved (TLC monitoring,
w60 min). Dipropyl adipate was isolated as described in the ex-
periment under Table 2. The yield was 65%.
4.4. Influence of the H2SO4 concentration on the time
of complete conversion of bishydroperoxide 2b and the yield
of dibutyl adipate 4b (Table 3)
4.9. Oxidation of ketones 1a–g in the optimized conditions:
synthesis of ethers 4a–g (Table 4)
Under analogous conditions, the influence of the H2SO4 con-
centration on the time of complete conversion of bishydroperoxide
2b and the yield of dibutyl adipate 4b was studied. The experiments
were carried out at the boiling point (98–100 ꢀC) by varying the
Hydrogenperoxide (5.5 g, 60 mmol, aqueous solution) and H2SO4
(1.2 g, 12 mmol) or H2O2 (34 g, 60 mmol, ethereal solution) and
H2SO4 (1.1 g, 11 mmol) were added to BuOH (20 mL). In the reaction

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tallics 1994, 13, 3442–3451; (d) Strukul, G.; Varagnolo, A.; Pinna, F. J. Mol. Catal.
A: Chem. 1997, 117, 413–423; (e) Lopp, M.; Paju, A.; Kanger, T.; Pehk, T. Tetra-
hedron Lett. 1996, 37, 7583–7586.
with the use of an ethereal solution, diethyl ether was distilled off
from the reaction mixture under reduced pressure (w100 Torr) at
room temperature. Then ketones 1a–g (10 mmol) were added with
stirring at 15–25 ꢀC for 5 min. The reaction mixture was heated at the
boiling point (102–106 ꢀC (anhydrous reaction mixture) and 98–
100 ꢀC (aqueous reaction mixture)) for 20 (1a–e) or 40 (1f,g) min and
cooled, CHCl3 (100 mL) was added, and the mixture was refluxed
using a Dean–Stark trap until water was completely removed. The
reaction solution was washed with saturated aqueous NaHCO3 to pH
7–8. The organic layer was separated, washed withwater (4ꢁ50 mL),
dried over MgSO4, and filtered. The filtrate was concentrated. Esters
4a–g were isolated by silica gel chromatography.
4. (a) van Berkel, W. J. H.; Kamerbeek, N. M.; Fraaije, M. W. J. Biotechnol. 2006, 124,
ꢀ
670–689; (b) Cernuchova´, P.; Mihovilovic, M. D. Org. Biomol. Chem. 2007, 5,
1715–1719; (c) Mihovilovic, M. D.; Mu¨ller, B.; Stanetty, P. Eur. J. Org. Chem. 2002,
3711–3730; (d) Kamerbeek, N. M.; Janssen, D. B.; van Berkel, W. J. H.; Fraaije, M.
W. Adv. Synth. Catal. 2003, 345, 667–678; (e) Stewart, J. D. Curr. Org. Chem. 1998,
2, 211–232; (f) Stewart, J. D.; Reed, K. W.; Kayser, M. M. J. Chem. Soc., Perkin
Trans. 1 1996, 755–757; (g) Mihovilovic, M. D. Curr. Org. Chem. 2006, 10, 1265–
1287.
5. Criegee, R. Justus Liebigs Ann. Chem. 1948, 560, 127–135.
6. Starcher, P. S.; Phillips, B. J. Am. Chem. Soc. 1958, 80, 4079–4082.
7. (a) Johnson, R. W.; Pollock, C. M.; Cantrell, R. R. Kirk-Othmer Encyclopedia of
Chemical Technology, 4th ed.; Krodchwitz, J., Ed.; John Wiley & Sons: New York,
NY, 1993; Vol. 8; (b) Suresh, A. K.; Sharma, M. M.; Sridhar, T. Ind. Eng. Chem. Res.
2000, 39, 3958–3997; (c) Castellan, A.; Bart, J. C. J.; Cavallarro, S. Catal. Today
1991, 9, 237–254, 255–283, 285–299, 301–322; (d) Chevilenko, I. S.; Preo-
brazhenskii, V. A.; Medvedeva, V. F.; Kaimina, N. D. J. Appl. Chem. U.S.S.R. (Engl.
Transl.) 1982, 55, 2492–2495; [ Zh. Prikl. Khim. (Leningrad) 1982, 55, 2742–2746 ].
8. (a) Pelletier, S. W.; Iyer, K. N.; Chang, C. W. J. J. Org. Chem. 1970, 35, 3535–3538;
(b) Hermann, P. (du Pont). U.S. Patent 2,341,288, 1944.
9. (a) Usui, Y.; Sato, K. Green Chem. 2003, 5, 373–375; (b) Zhu, W.; Li, H.; He,
X.; Zhang, Q.; Shu, H.; Yan, Y. Catal. Commun. 2008, 9, 551–555; (c) Carraro,
M.; Sandei, L.; Sartorel, A.; Scorrano, G.; Bonchio, M. Org. Lett. 2006, 8, 3671–
3674.
10. (a) He, L.; Horiuchi, C. A. Bull. Chem. Soc. Jpn. 1999, 72, 2515–2522; (b) Mehrotra,
R. N. Indian J. Chem., Sect. A 1983, 22, 169–172.
The preparation and data for diethyl hexanedioate,20 ethyl 6-
hydroxyhexanoate,21 dipropyl hexanedioate,22 dibutyl pentane-
dioate (4a),23 dibutyl hexanedioate (4b),23 dibutyl heptanedioate
(4e),23 dibutyl octanedioate (4f),24 and dibutyl dodecanedioate
(4g)25 have been previously reported.
4.9.1. Dibutyl 3-metylhexanedioate, 4c
1H NMR (250.13 MHz, CDCl3),
d: 0.83–0.96 (m, 9H, CH3), 1.23–
1.70 (m, 11H, CH2), 2.20–2.35 (m, 4H, CH2COOBu), 4.03 (t, 4H,
COOCH2, J¼6.7 Hz). 13C NMR (75.4 MHz, CDCl3),
d: 13.6 (CH3), 17.0
11. Roundhill, D. M.; Dickson, M. K.; Dixit, N. S.; Sudha-Dixit, B. P. J. Am. Chem. Soc.
1980, 102, 5538–5542.
(CH3), 19.1, 19.3, 28.6, 29.9, 30.5, 30.6, 31.5 (CH2), 31.9, 41.4
(CH2COOBu), 64.1, 64.2 (OCH2Pr), 172.8, 173.5 (C]O). MS (EI), m/z
(Irel (%)): 273 [MþH]þ (15), 199 [MꢂBuO]þ (71), 143 [MꢂBuOꢂBu]þ
(44), 125 [Mꢂ2BuOꢂH]þ (53), 41 (100). Anal. Calcd for C15H28O4: C,
66.14; H, 10.36. Found: C, 66.20; H, 10.68.
12. (a) Wolfe, S.; Ingold, C. F. J. Am. Chem. Soc. 1983, 105, 7755–7757; (b) Amend, W.
J. (du Pont de Nemours & Co.). U.S. Patent 2,316,543, 1943; (c) Nagori, R. R.;
Mehta, M.; Mehrotra, R. N. J. Chem. Soc., Dalton Trans. 1981, 581–585; (d) Cha-
van, S. A.; Srinivas, D.; Ratnasamy, P. J. Catal. 2002, 212, 39–45; (e) Shimizu, A.;
Tanaka, K.; Ogawa, H.; Matsuoka, Y.; Fujimori, M.; Nagamori, Y.; Hamachi, H.;
Kimura, K. Bull. Chem. Soc. Jpn. 2003, 76, 1993–2001.
13. Gauthard, F.; Horvath, B.; Gallezot, P.; Besson, M. Appl. Catal., A: General 2005,
279, 187–193.
14. Bre´geault, J.-M.; Launay, F.; Atlamsani, A. C. R. Acad. Sci., Ser. IIc: Chim. 2001, 4,
11–26.
15. Terent’ev, A. O.; Platonov, M. M.; Ogibin, Y. N.; Nikishin, G. I. Synth. Commun.
2007, 37, 1281–1287.
16. Terent’ev, A. O.; Platonov, M. M.; Kutkin, A. V. Cent. Eur. J. Chem. 2006, 4, 207–
215.
4.9.2. Dibutyl 3-tert-butylhexanedioate, 4d
1H NMR (250.13 MHz, CDCl3),
d: 0.79–0.97 (m, 15H, CH3), 1.21–
1.73 (m, 11H, CH2), 2.18–2.44 (m, 4H, CH2COOBu), 4.02 (t, 4H,
COOCH2, J¼6.8 Hz). 13C NMR (75.4 MHz, CDCl3),
d: 13.6 (CH3), 19.07,
19.1, 26.3, 27.2, 30.5, 30.6 (CH2), 33.4 (C), 33.6, 35.7 (CH2COOBu), 44.4
(CH), 64.1, 64.2(OCH2Pr),173.6,174.1 (C]O).MS(EI), m/z(Irel (%)):315
[MþH]þ (11), 241 [MꢂBuO]þ (19),167 [Mꢂ2BuOꢂH]þ (20), 41 (100).
Anal. Calcd for C18H34O4: C, 68.75; H,10.90. Found: C, 68.51; H,10.87.
17. (a) Vennerstrom, J. L.; Fu, H.-N.; Ellis, W. Y.; Ager, A. L.; Wood, J. K.; Andersen,
S. L.; Gerena, L.; Milhous, W. K. J. Med. Chem. 1992, 35, 3023–3027; (b)
ˇ
Zmitek, K.; Zupan, M.; Iskra, J. Org. Biomol. Chem. 2007, 5, 3895–3908; (c)
ˇ
Zmitek, K.; Zupan, M.; Stavber, S.; Iskra, J. J. Org. Chem. 2007, 72, 6534–6540;
(d) Jefford, C. W.; Li, Y.; Jaber, A.; Boukouvalas, J. Synth. Commun. 1990, 20,
2589–2596; (e) Terent’ev, A. O.; Kutkin, A. V.; Platonov, M. M.; Ogibin, Y. N.;
Nikishin, G. I. Tetrahedron Lett. 2003, 44, 7359–7363; (f) Opsenica, D.; Pocs-
falvi, G.; Juranic, Z.; Tinant, B.; Declercq, J.-P.; Kyle, D. E.; Milhous, W. K.;
Solaja, B. A. J. Med. Chem. 2000, 43, 3274–3282; (g) Kim, H.-S.; Tsuchiya, K.;
Shibata, Y.; Wataya, Y.; Ushigoe, Y.; Masuyama, A.; Nojima, M.; McCullough, K.
J. Chem. Soc., Perkin Trans. 1 1999, 1867–1870; (h) Amewu, R.; Stachulski, A. V.;
Ward, S. A.; Berry, N. G.; Bray, P. G.; Davies, J.; Labat, G.; Vivas, L.; O’Neill, P.
M. Org. Biomol. Chem. 2006, 4, 4431–4436; (i) Hamada, Y.; Tokuhara, H.;
Masuyama, A.; Nojima, M.; Kim, H.-S.; Ono, K.; Ogura, N.; Wataya, Y. J. Med.
Chem. 2002, 45, 1374–1378.
Acknowledgements
This work is supported by the Program for Support of Leading
Scientific Schools of the Russian Federation (Grant NSh
2942.2008.3), the Grant of President of Russian Federation (MK-
3515.2007.3) and the Russian Science Support Foundation.
References and notes
18. Saito, I.; Nagata, R.; Yuba, K.; Matsuura, T. Tetrahedron Lett. 1983, 24, 1737–1740.
19. Kim, H.-S.; Nagai, Y.; Ono, K.; Begum, K.; Wataya, Y.; Hamada, Y.; Tsuchiya,
K.; Masuyama, A.; Nojima, M.; McCullough, K. J. Med. Chem. 2001, 44, 2357–
2361.
1. (a) Baeyer, A.; Villiger, V. Ber. Dtsch. Chem. Ges. 1899, 32, 3625–3633; (b) Baeyer,
A.; Villiger, V. Ber. Dtsch. Chem. Ges. 1900, 33, 858–864.
20. Ballini, R.; Bosica, G. Tetrahedron 1997, 53, 16131–16138.
21. Yoon, N. M.; Pak, C. S.; Brown, H. C.; Krishnamurthy, S.; Stocky, T. P. J. Org. Chem.
1973, 38, 2786–2792.
22. Vogel, A. I. J. Chem. Soc. 1948, 624–644.
23. Serwy, H. Bull. Soc. Chim. Belg. 1933, 42, 483–501.
2. (a) Krow, G. R. Organic Reactions; Paquette, L., Ed.; John Wiley and Sons: 1993;
Vol. 43, pp 251–798; (b) Renz, M.; Meunier, B. Eur. J. Org. Chem. 1999, 737–750;
(c) Belov, V. N.; Heyfitz, L. A.; Virezub, S. I. Reaczii I Metodi issledovaniya
organicheskich soedineniy; Goshimizdat: Moscow, 1961; Vol. 10, pp 7–208.
3. (a) Bolm, C.; Schlingloff, G.; Weickhardt, K. Angew. Chem., Int. Ed. Engl. 1994, 33,
1848–1849; (b) Bolm, C.; Schlingloff, G.; Bienewald, F. J. Mol. Catal. A: Chem.
1997, 117, 347–350; (c) Gusso, A.; Baccin, C.; Pinna, F.; Strukul, G. Organome-
24. Nishiguchi, T.; Ishii, Y.; Fujisaki, S. J. Chem. Soc., Perkin Trans. 1 1999, 3023–3027.
25. Marosi, L.; Schlenk, W. Justus Liebigs Ann. Chem. 1973, 584–598.