Electrooxidative transformation of unsubstituted and substituted nitro hydrocarbons into carbonyl compounds

Article abstract of DOI:10.1023/A:1020906805561

Alkaline salts of aci-forms of secondary nitro compounds, viz., β-nitropropylbenzene, nitrocyclohexane, 5-nitroheptan-2-one, and methyl-4-nitrohexanoate, were selectively or predominately oxidized into the corresponding ketones and their ketals under conditions of undivided amperostatic electrolysis in methanol. Mixtures of the corresponding aldehydes, their acetals, and methyl carboxylates were formed under similar conditions from the salts of primary nitro compounds, viz., 1-nitrohexane, nitromethylbenzene, and β-nitroethylbenzene.

Full text of DOI:10.1023/A:1020906805561

1
460
Russian Chemical Bulletin, International Edition, Vol. 51, No. 8, pp. 1460—1465, August, 2002
Electrooxidative transformation of unsubstituted and substituted
nitro hydrocarbons into carbonyl compounds
ꢀ
Yu. N. Ogibin, A. I. Ilovaiskii, V. M. Merkulova, A. O. Terent´ev, and G. I. Nikishin
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
4
7 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (095) 135 5328. Eꢀmail: ogibin@ioc.ac.ru
Alkaline salts of aciꢀforms of secondary nitro compounds, viz., βꢀnitropropylbenzene,
nitrocyclohexane, 5ꢀnitroheptanꢀ2ꢀone, and methylꢀ4ꢀnitrohexanoate, were selectively or
predominately oxidized into the corresponding ketones and their ketals under conditions of
undivided amperostatic electrolysis in methanol. Mixtures of the corresponding aldehydes,
their acetals, and methyl carboxylates were formed under similar conditions from the salts of
primary nitro compounds, viz., 1ꢀnitrohexane, nitromethylbenzene, and βꢀnitroethylbenzene.
Key words: nitrocyclohexane, 1ꢀnitrohexane, nitromethylbenzene, αꢀ and βꢀnitroꢀ
ethylbenzenes, βꢀnitropropylbenzene, 5ꢀnitroheptanꢀ2ꢀone, methyl 4ꢀnitrohexanoate, salts
of аciꢀnitro compounds, electrolysis, ketones, carboxylates, vicꢀdinitroalkanes.
The present work is devoted to the electrooxidative
into carbonyl compounds remains unclear, and the choice
of electrolysis conditions providing the selective transꢀ
formation of unsubstituted and functionally substituted
nitro hydrocarbons into target products depends on the
solution of this problem.
transformation of unsubstituted and substituted nitro hyꢀ
drocarbons into carbonyl compounds. This electrochemiꢀ
cal process is poorly studied, although, according to availꢀ
able data, can be very useful from the synthetic point of
view.1 The chemical prototype of the process is the
—3
It was assumed until the present study that the
electrogenerated nitroalkyl radicals are transformed into
carbonyl compounds due to decomposition with nitroꢀ
4
Nef reaction, which has been known for more than a
5
—19
century, with its numerous modifications
developed
2
1,22
to create more perfect than the Nef reaction methods for
the transformation of the nitro group into the carbonyl
group. In the most cases, these methods are based on the
oneꢀ and twoꢀelectron oxidation of aciꢀnitro compounds
gen monoxide elimination.
Since this reaction is
chemical, it should not be affected noticeably by the
anodic current density and the material of the anode.
However, this contradicts explicitly the later data, which
demonstrated an evident interrelation between the conꢀ
6
2–
+
7
using diaroyl peroxides, S2O8 —Ag systems, alkyl
8
9,10
1,2
nitrites, and ammonium cerium nitrate
tron oxidants and potassium permanganate,
chlorite, Caro´s acid (Oxone), dimethyldioxirane,
singlet oxygen,16 ozone, and oxidative systems ruꢀ
as oneꢀelecꢀ
ditions and results of electrolysis. It is established, for
1
1,12
sodium
example, that the electrochemical transformation of nitro
compounds into carbonyl compounds, similarly to the
Kolbe reaction, occurs most efficiently at high anodic
current densities and when polished platinum is used as
the anode. These facts indicate a mechanism different
1
3
14
15
17
1
8
thenate(perruthenate) anions—potassium bromate,
tetrapropylammonium perrruthenate—Nꢀmethylmorphoꢀ
lineꢀNꢀoxide,19 and tertꢀbutyl hydroxyperoxide—diꢀ
21,22
from that considered previously.
2
0
acetyl complex of vanadium oxide as twoꢀelectron
oxidants.
The purpose of this work is to establish the general
regularities of the electrooxidative transformation of
unsubstituted and substituted nitro hydrocarbons into
carbonyl compounds, to study the influence of the strucꢀ
ture of the initial substrates and electrolysis conditions
on the composition of the products, and to reveal some
aspects of the mechanism of this process using the reꢀ
sults obtained.
We chose 1ꢀnitrohexane (1a); nitromethylꢀ (1b),
βꢀ and αꢀnitroethylꢀ (1c,d), and βꢀnitropropylbenzene
(1e); nitrocyclohexane (1f); 5ꢀnitroheptanꢀ2ꢀone (1g);
and methyl 4ꢀnitrohexanoate (1h) as the initial comꢀ
It is known that αꢀnitroalkyl radicals are generated at
the initial stage of both the electrochemical and oneꢀ
2
1
electron oxidation of aciꢀnitro hydrocarbons. This is
indicated by the formation of dimers of these radicals,
viz., α,βꢀdinitroalkanes, which were obtained in many
cases as the main electrolysis product. Therefore, it seems
reasonable to assume the intermediate involvement of
the αꢀnitroalkyl radicals in the electrochemical transforꢀ
1
—3
mation of nitroalkanes into carbonyl compounds.
However, the question how such radicals are transformed
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1348—1353, August, 2002.
066ꢀ5285/02/5108ꢀ1460 $27.00 © 2002 Plenum Publishing Corporation
1

Electrotransformation of nitro hydrocarbons
Russ.Chem.Bull., Int.Ed., Vol. 51, No. 8, August, 2002
1461
pounds. They were electrolyzed as sodium, potassium,
or ammonium salts of the corresponding aciꢀnitro comꢀ
pounds 2а—h. The ammonium salts were prepared by
the reactions of compounds 1а,g,h with DBU. In the
most cases, electrolysis was carried out in methanol usꢀ
ing the galvanostatic regime, undivided cells, a platinum
anode, and a steel cathode. The electrolysis conditions
were varied. Graphite and glassyꢀcarbon were also used
as the anodic material. The conversion of the substrates
and the composition, structure, and yields of the prodꢀ
ucts were estimated in experiments. The results obtained
are presented in Table 1. The structures of the main
products are shown in Scheme 1.
The GLC analysis of the electrolyzates showed that
the electrolysis under the indicated conditions resulted
in the transformation of the salts of secondary aciꢀnitro
compounds 2d—h mainly into the corresponding ketones
3d—h and their ketals in the ratio from 1 : 1 to 2 : 1,
whereas the salts of primary aciꢀnitro compounds 2a—c
are transformed into aldehydes 3а—с, their acetals (in a
ratio of ∼1 : 1), methyl carboxylates 4а—с, and considerꢀ
able amounts of resinous products. To estimate the overꢀ
all yield of the carbonyl compounds and their derivaꢀ
tives, the latter were transformed into ketones and aldeꢀ
hydes by the treatment of the electrolyzate with a soluꢀ
tion of HCl. Dimers of αꢀnitroalkyl radicals 5 and 6
Table 1. Electrolysis of salts of aciꢀnitro compounds 2а—h in MeOH (a Pt anode and a steel cathode, galvanostatic regime,
0—15 °C)
1
a
Entry
Substrate
Source of
counterion (equiv.)
Current density
/mA cm–2
Conversion
(%)
Q
Yield (%) (Product)
/F mol–1
3
4
5, 6
1
2
3
2a
2a
2a
2a
2a
2b
MeONa (2)
MeONa (2)
KF (2)
MeONa (1)
DBU (1)
100
100
100
100
100
95
100
91
92
90
100
95
50
85
87
95
90
95
100
99
100
100
94
100
97
100
96
80
2
3
2
2
2
2
2
2
2
2
2
2
4
3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
18 (3a)
10 (3a)
8 (3a)
56 (4a) 10 (5)
58 (4a)
74 (4a)
3 (5)
5 (5)
1 (5)
3 (5)
—
b
с
4
4 (3a)
73 (4a)
43 (4a)
20 (4b)
25 (4b)
—
5
6
7
8
9
29 (3a)
10 (3b)
25 (3b)
—
d
MeONa (1)
MeONa (2)
MeONa (1)
MeONa (2)
MeONa (1)
MeONa (2)
MeONa (2)
MeONa (1)
MeONa (1)
MeONa (1)
MeONa (2)
MeONa (1)
MeONa (1)
KOH (2)
MeONa (1)
MeONa (1)
MeONa (1)
DBU (1)
MeONa (1)
MeONa (1)
MeONa (1)
MeONa (1)
MeONa (2)
MeONa (1)
DBU (1)
20
PhCH=NOH
100
100
100
100
100
50
—
e
PhCHO
2c
2d
2e
2e
2f
60
17 (3c)
78 (3d)
81 (3e)
62 (3e)
63 (3f)
94 (3f)
95 (3f)
80 (3f)
89 (3f)
82 (3f)
86 (3f)
52 (3f)
65 (3f)
45 (3f)
92 (3g)
87 (3g)
90 (3g)
77 (3g)
80 (3h)
78 (3h)
88 (3h)
90 (3h)
48 (4c)
—
—
—
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
—
—
c
—
—
65
—
—
—
—
—
—
—
—
2 (6)
2 (6)
2 (6)
2 (6)
3 (6)
6 (6)
1.5 (6)
3 (6)
3 (6)
2.5 (6)
—
2f
2f
2f
2f
2f
2f
2f
2f
100
100
100
150
200
100
100
100
100
100
100
100
100
100
100
100
100
c
f
—
—
—
g
2f
2g
2g
2g
2g
2h
2h
2h
2h
100
75
100
90
85
85
—
—
c
f
—
—
—
—
—
—
—
—
f
—
—
82
—
—
а
b
c
d
e
f
Calculated per transformed substrate.
Potassium salt.
Graphite anode.
At a current density of 100 mA cm–2 only resinous products are formed.
1
,2ꢀDiphenylethanediol.
Glassyꢀcarbon anode.
Electrolysis at 60 °С.
g

1462
Russ.Chem.Bull., Int.Ed., Vol. 51, No. 8, August, 2002
Ogibin et al.
Scheme 1
R1 = H, R2 = nꢀC H (a); R = H, R2 = Ph (b); R1 = H, R2 = Bn (c); R1 = Me, R2 = Ph (d);
1
5
11
R1 = Me, R2 = Bn (e); R + R2 = (CH2)5 (f); R1 = Et, R2 = CH CH Ac (g); R = Et, R2 = CH CH CO Me (h)
1
1
2
2
2
2
2
Reagents and conditions: i. МеОН, MeONa, КОН, or DBU (1—2 equiv.), ∼20 °С; ii. МеОН, 2—4 F mol–1, 10—15 °С;
iii. Acidification of reaction mixture.
were formed only in the case of the electrolysis of subꢀ
strates 2a and 2f, respectively (see Table 1).
their yield decrease when graphite and glassyꢀcarbon are
used instead of platinum (the conversion decreases by
3—25% and the yield increases by 10—28%, see Table 1,
entries 12, 20, 21, 25, 26, and 29). The yield of carbonyl
products decreases when electrolysis is carried out at
60 °С instead of 10—15 °С.
The peculiarities mentioned for the process under
study, several common features with the Kolbe reaction
(a similar plot of the yields of electrolysis products vs.
current density at the anode and material of the anꢀ
ode, etc.) favor that the electrolysis of salts 2а—h generꢀ
ates the nitronate (А) and αꢀnitroalkyl radicals (В) folꢀ
lowed by their transformation through the intermediate
formation of esters of nitronic acids into identified prodꢀ
ucts 3а—h and 4a—с (Scheme 2).
The salt of the aciꢀnitro compound obtained by the
preliminary interaction of the initial compound with the
equimolar or excessive amount of a solution of MeONa
or KOH in MeOH acts simultaneously as the reactant
and electrolyte. This feature of the process in combinaꢀ
tion with the regeneration of the alkaline metal methoxide
during electrolysis allows one to avoid the use of other
electrolytes and to achieve the ∼100% conversion of the
salt of the aciꢀnitro compound at anodic current densiꢀ
–
2
ties of 65—200 mA cm even when the theoretical
–
1
amount of electricity (2 F mol ) is passed (see Table 1).
This conversion to be achieved at lower current densiꢀ
ties requires the greater consumption of electricity to
–2
3
—4 F mol–1. The anodic current density >150 mA cm
Evidently, the dimerization of radicals В occurs simulꢀ
taneously to form vicinal dinitro compounds 5 and 6.
favors the formation of the dimers of the αꢀnitroalkyl
radicals (see Table 1, entries 14—19). At the optimum
The size of substituents at the С atom of the initial
α
–
2
anodic current density (100—150 mA cm ) the yield of
nitro compound has a substantial effect on the ratio of
radical crossꢀ and homocoupling processes, which deꢀ
termines the formation of the main (see Scheme 2) and
byꢀproducts of electrolysis: the more bulky the substituꢀ
dimers 6 and 5 does not exceed 2% for salt 2f and achieves
5
—10% for salt 2а, respectively (see Table 1, entries 1
and 2). The conversion of salts 2 to products 3—6 and

Electrotransformation of nitro hydrocarbons
Russ.Chem.Bull., Int.Ed., Vol. 51, No. 8, August, 2002
1463
Scheme 2
Scheme 4
benzaldehyde and methyl benzoate were the main elecꢀ
trolysis products (see Table 1, entry 7). It was also found
experimentally (see Table 1, entry 8) that methyl benꢀ
zoate was not formed upon the undivided electrolysis of
benzaldehyde in MeOH against the background of
MeONa. In this case, PhCHO is transformed into
В is base
1
,2ꢀdiphenylethaneꢀ1,2ꢀdiol. These observations confirm
indirectly that products 3а—с and 4а—с can be formed
ents, the lower the contribution of the side reaction. The
steric effect hinders, most likely, the transformation of
radicals А into В and, on the contrary, these are the
main products upon the electrooxidation of salts of lower
aciꢀnitroalkanes.21
through oximes but only partially because their total yield
2
cannot exceed 50%. The absence of R C(O)NO in the
2
electrolysis products is due to their transformation into
esters 4а—с by methanol.
Another possible reason for the absence of oximes in
the products of electrolysis of salts 2а—с is that the deꢀ
composition of dimers АВ can proceed via a mechanism
different from that presented in Scheme 3. This possibilꢀ
We assume that dimers АВ are intermediates of the
electrochemical transformation of the salts of the aciꢀnitro
compounds into the identified products. They are alkyl
esters of nitronic acids. It is known2
3,24
that esters of this
2
3
ity has also been mentioned previously. Perhaps, the
decomposition of dimers АВ is preceded by ester interꢀ
change with methanol and the transformation of methyl
nitronates 8 into substituted nitrocarbinols 9 and 10.
The final products, viz., ketones, ketals, and esters, are
formed in the subsequent transformations of intermediꢀ
ate products 8—10 (Scheme 5).
type, especially those obtained from salts of secondary
aciꢀnitro compounds, decompose readily. For example,
the esters with the С—Н bond in the αꢀposition to the
ester oxygen disproportionate at room temperature to
form ketones and oximes (Scheme 3).
Scheme 3
Esters can be formed in the electrolysis of salts of
primary aciꢀnitro compounds also due to the transforꢀ
mations of αꢀnitroalkyl radicals В (R = H) presented in
1
Scheme 6.
We hope to obtain arguments in favor of the proꢀ
posed alternative mechanism in our further studies.
The behavior of the radicals generated by the elecꢀ
trolysis of salts 2b,d,f differs substantially from that of
the radicals obtained by the oneꢀelectron oxidation of
these salts. This difference is resulted by the fact that a
much higher concentration of radicals than the average
concentration in the solution is created near the elecꢀ
trode due to the electrochemical reaction, while in the
chemical reaction the radical concentration is approxiꢀ
mately the same and very low in all points of the reaction
medium. As a result, the predominant direction of transꢀ
formation of the radicals generated in the electrochemiꢀ
cal process is crossꢀcoupling, while in the chemical proꢀ
Taking into account this fact, esters 4а—с and oximes
7
а—с should be expected as products of the similar reacꢀ
1
tion of the corresponding dimer АВ (R = H) upon the
electrolysis of salts of primary aciꢀnitro hydrocarbons
2
а—с (Scheme 4). However, they were not found in the
electrolysis products.
This can be reasoned, in particular, by the efficient
electrochemical transformation of these compounds into
other products. For example, in the model experiment
the conversion of benzaldehyde oxime was 95%, and

1464
Russ.Chem.Bull., Int.Ed., Vol. 51, No. 8, August, 2002
Ogibin et al.
Scheme 5
cess it is homocoupling and the interaction with compoꢀ
nents of the medium, including oneꢀelectron oxidants
and intermediate products of their decomposition. The
oneꢀelectron oxidation of salt 2b with silver nitrate,
2
5,26
2–
+
7
peroxydisulfates,
and the S O8 —Ag system in an
2
alkaline medium affords at first dimers of αꢀnitrobenzyl
radicals and dimers of the latter with the corresponding
nitronate radicals and sulfate radical anions. Then these
dimers are transformed into nitrostilbene and benzaldeꢀ
7
hyde, which are formed in 58 and 23% yields, respecꢀ
tively, and partially into 1ꢀnitroꢀ2ꢀbenzylstilbene (2%)
and 3,4,5ꢀtriphenylisoxazole (2.4%). If the oneꢀelectron
oxidation of the salts of αꢀaciꢀnitroalkylbenzenes, for
example, 2b,d, with silver nitrate is performed in a neuꢀ
tral medium (DMSO), the primary and secondary
αꢀnitrobenzyl radicals generated from these salts are
transformed into 3,4,5ꢀtriphenylꢀ4,5ꢀdihydroisoxazole
2
6
Nꢀoxide and 2,3ꢀdinitroꢀ2,3ꢀdiphenylbutane, respecꢀ
tively (Scheme 7).
Scheme 7
R = H (b), Me (d)
The oxidation of salt 2f under these conditions also
affords26 only one product, viz., 1,1´ꢀdinitrobicyclohexane
(
6). Salt 2f in a weakly alkaline medium is transformed7
by K S O into cyclohexanone and dimer 6 in 67 and
2
2
8
1
4—30% yields, respectively.
Thus, the data obtained suggest that the electrolysis
of the salts of the aciꢀnitro compounds in methanol genꢀ
erates both the αꢀnitroalkyl radicals and mesomeric
nitronate radicals, and the subsequent transformation of
these radicals into the carbonyl compounds proceeds, at
least partially, through the intermediate formation of
esters of nitronic acids. For the salts of the secondary
aciꢀnitro compounds this process is an electrochemical
variant of the Nef reaction, providing the yield of keꢀ
tones up to 95%, which confers it a preparative value.
Scheme 6
Experimental
NMR spectra were recorded on a Bruker WMꢀ250 specꢀ
trometer (250 MHz) in СDCl . IR spectra were recorded on a
3
Specord Mꢀ80 instrument in ССl . GLC analysis was carried
4

Electrotransformation of nitro hydrocarbons
Russ.Chem.Bull., Int.Ed., Vol. 51, No. 8, August, 2002
1465
out on a Varianꢀ3700 chromatograph (a flameꢀionization deꢀ
tector, glass columns, 5% Carbowax 20M on Inerton and
References
5
% XEꢀ60 on Chromaton NꢀAW). Silufol UVꢀ254 plates were
1
. J. Nokami, T. Sonoda, and S. Wakabayashi, Synthesis,
983, 763.
. T. Miyakoshi, Synthesis, 1986, 766.
. T. Miyakoshi, J. Jpn. Oil Chemist’s Soc. (Yukagaku),
988, 37, 19.
4. J. U. Nef, Ann., 1894, 280, 263.
. W. E. Noland, Chem. Rev., 1955, 55, 137; H. W. Patrick,
Org. React., 1990, 38, 665.
. C.ꢀX. Zhao, Acta Chim. Sinica, 1987, 45, 83 (RZhKhim
used for TLC. Silica gel L 40/100 µm was used for flash chroꢀ
matography (eluent hexane—AcOEt (1—5%)).
1
2
3
Commercial 1ꢀnitrohexane (1a), nitrocyclohexane (1f), and
DBU (Aldrich) were used. Methanol was dehydrated by distilꢀ
lation above Mg(OMe) . Nitromethylꢀ (1b) , βꢀ and αꢀnitroꢀ
ethylꢀ (1c,d) , βꢀnitropropylbenzene (1e) , 2ꢀnitroheptanꢀ
1
5
2
2
7
28
5
ꢀone (1g)29, and methyl 4ꢀnitrohexanoate (1h) were syntheꢀ
sized using known procedures. vicꢀ6,7ꢀDinitrododecane (5) and
,1´ꢀdinitrobicyclohexane (6) used as reference compounds in
GLC analysis of electrolysis products were prepared from salts
30
2
6
1
[
Abstract Journal of Chemistry], 1988, 8Zh91 (in Russian));
C.ꢀX. Zhao, Y. Qu, and X. Jiang, Chin. J. Org. Chem., 1988,
7
2
а,f using a previously published procedure.
8
, 514 (RZhKhim [Abstract Journal of Chemistry], 1989,
Electrolysis of salts of aciꢀnitro compounds (general proceꢀ
8
Zh117 (in Russian)).
dure). Nitro compound 1 (2—5 mmol) was dissolved in 20 mL
of a solution of MeONa, КОН, or DBU (1—2 equiv.) in MeOH,
and the mixture was stirred until the substrate transformed
completely into the salt of its aciꢀform (0.5 h). Electrolysis was
carried out in a undivided electrolyzer at a constant temperature
7
8
9
. A. H. Pagano and H. Shechter, J. Org. Chem., 1970, 35, 295.
. N. Kornblum and P. A. Wade, J. Org. Chem., 1973, 38, 1418.
. G. A. Olah and B. C. Gupta, Synthesis, 1980, 44.
1
1
0. N. Arai and K. Narasaka, Chem. Lett., 1995, 987.
1. H. Shechter and F. T. Williams, J. Org. Chem., 1962, 27,
2
with a platinum, graphite, or glassyꢀcarbon anode (S = 3 cm )
3
699; F. Freeman and D. K. Lin, J. Org. Chem., 1971,
6, 1335.
2
and a stainless steel cathode (S = 3 cm ), which were remote at
3
a distance of 3—5 mm, with vigorous stirring of the reaction
mixture under conditions presented in Table 1. Electrolyzates
were diluted with water (20 mL), acidified with AcOH (1 mL)
to transform unreacted salt 2 into the initial compound, and
1
1
2. R. Ballini and M. Petrini, Tetrahedron Lett., 1989, 30, 5329.
3. R. Ballini, G. Bosica, and F. Gigli, Tetrahedron, 1998,
5
4, 7573.
1
1
1
1
1
4. P. Ceccherelli, M. Curini, F. Epifano, M. C. Marcotullio,
and O. Rosati, Synth. Commun., 1998, 28, 3057.
5. W. Adam, M. Mikosza, C. R. SahaꢀMiller, and C.ꢀG. Zhao,
Synlett, 1998, 1335.
6. J. R. Williams, L. G. Anger, and R. H. Moore, J. Org.
Chem., 1978, 43, 1271.
extracted with CHCl (2×20 mL). An aliquot was taken from
3
the combined extracts, dried above potash, and analyzed by
GLC using authentic reference compounds (according to the
data of analysis, under these conditions salts 2d—h are mainly
transformed into ketones 3d—h and their ketals, whereas salts
2
a—c are transformed into aldehydes 3а—с, their acetals, and
7. J. E. McMurry, J. Melton, and H. Padgett, J. Org. Chem.,
esters 4а—с). To hydrolyze ketals and acetals, the remaining
portion of the combined extracts was stirred for 0.5 h with a
1
974, 39, 259.
8. A. J. Bailey, W. P. Griffith, S. Mostafa, and P. A. Sherwood,
Inorg. Chem., 1993, 32, 268.
2
М solution of НСl (10 mL), neutralized with a 5% solution of
NaHCO (10 mL), and dried above potash. The yield of carboꢀ
3
19. Y. Tokunaga, I. Masataka, and K. Fukumoto, J. Chem.
Soc., Perkin Trans. 1, 1997, 207.
2
nyl compounds 3а—h, esters 4а—с, and dinitroalkanes 5 and 6
was determined by GLC using an internal reference (dodecane,
hexadecane). Products 3g and 3h were identified by the IR
0. P. A. Bartlett, F. R. Green, III, and T. R. Webb, Tetraꢀ
hedron Lett., 1977, 331.
1. V. A. Kokorekina, V. A. Petrosyan, and L. G. Feoktistov,
Elektrosintez monomerov [Electrosynthesis of Monomers],
Nauka, Moscow, 1980, 83 (in Russian).
1
13
spectra and Н and С NMR spectra of the preparations isoꢀ
lated by flash chromatography on silica gel.
2
Heptaneꢀ2,5ꢀdione (3g).1
6,17
IR, ν/cm : 1735. Н NMR,
δ: 1.02 (t, 3 Н, J = 7 Hz); 2.17 (s, 3 H); 2.45 (q, 2 Н, J = 7 Hz);
.67 (m, 4 Н).
Methyl 4ꢀoxohexanoate (3h).20 IR, ν/cm–1: 1740. Н NMR,
δ: 1.01 (t, 3 Н, J = 7 Hz); 2.43 (q, 2 H, J = 7 Hz); 2.52 (t, 2 Н,
–1
1
2
2
2
2. S. Wawzonek and T.ꢀY. Su, J. Electrochem. Soc., 1973,
2
1
20, 745.
3. N. Kornblum and R. A. Brown, J. Am. Chem. Soc., 1964,
6, 2681.
4. L. G. Donaruna, J. Am. Chem. Soc., 1957, 72, 1024.
1
8
13
J = 6.5 Hz); 2.68 (t, 2 Н, J = 6.5 Hz); 3.61 (s, 3 Н). С NMR,
δ: 7.72 (Me); 27.78, 35.83, and 36.58 (СН ); 51.64 (ОMe);
2
25. H. Shechter and R. B. Kaplan, J. Am. Chem. Soc., 1953,
5, 3980.
2
1
73.17 (СОО); 209.20 (С=О).
7
Electrolysis of benzaldehyde and benzaldehyde oxime. These
6. K. Fukunaga and M. Kimura, J. Chem. Soc. Jpn., Chem.
Ind. Chem., 1982, 1499.
7. D. S. Bose and G. Vanajatha, Synth. Commun., 1998, 28, 4531.
8. A. B. Battersby, M. G. Baker, H. A. Broadbent, C. J. R.
Fookes, and F. J. Leeper, J. Chem. Soc., Perkin Trans. 1,
1987, 2027.
9. D. W. Chasar, Synthesis, 1982, 841; G. Rosini, E. Marotta,
R. Ballini, and M. Petrini, Synthesis, 1986, 237.
0. R. Ballini, M. Petrini, and G. Risini, Synthesis, 1987, 711.
experiments were carried out in MeOH in the presence of 1
equiv. of МеONa using the general procedure of electrolysis of
nitro compounds. The results are presented in Table 1.
2
2
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 00ꢀ03ꢀ
2
3
3
2871), the State Foundation for Support of Leading
Scientific Schools of Russia (Grant 00ꢀ15ꢀ97328), and
the Ministry of Industry, Science, and Technology (State
Contract No. 402ꢀ2.2/3.3/8.1/19.1/21.1/22.4(00ꢀP)).
Received December 13, 2001;
in revised form March 14, 2002