Solvent-free oxidation of aliphatic alcohols with ceric ammonium nitrate-lithium bromide system

Article abstract of DOI:10.1007/s11172-007-0232-8

Esters are formed during the solvent-free oxidation of primary aliphatic C₅-C₉ alcohols with Ce(NH₄)₂(NO ₃)₆-LiBr, whereas secondary octan-2-ol gives a mixture of isomeric 1-and 3-bromooctan-2-ones.

Full text of DOI:10.1007/s11172-007-0232-8

Russian Chemical Bulletin, International Edition, Vol. 56, No. 8, pp. 1501—1506, August, 2007
1501
Solventꢀfree oxidation of aliphatic alcohols
with ceric ammonium nitrate—lithium bromide system*
N. I. Kapustina,aꢀ L. L. Sokova,a R. G. Gasanov,b and G. I. Nikishina
аN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
47 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (499) 135 5328. Eꢀmail: kap@ioc.ac.ru
bA. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
28 ul. Vavilova, 119991 Moscow, Russian Federation
Esters are formed during the solventꢀfree oxidation of primary aliphatic С5—С9 alcohols
with Ce(NH4)2(NO3)6—LiBr, whereas secondary octanꢀ2ꢀol gives a mixture of isomeric 1ꢀ and
3ꢀbromooctanꢀ2ꢀones.
Key words: alkanols, ceric ammonium nitrate, lithium bromide, oxidation, solventꢀfree
reactions, esters, ketones.
Ceric ammonium nitrate (CAN) is one of the widely
used oxidizing agents. Recent years showed a noticeable
growth of interest to CAN due to a numerous literature
examples of functionalization and transformation of orꢀ
ganic compounds with its participation.1 Chemical beꢀ
havior of hydrocarbons, oxygenꢀcontaining aliphatic and
alicyclic compounds,2 and nitrogenꢀcontaining strucꢀ
tures3,4 was studied in oxidation reactions with CAN as
well as with CAN—I2 and CAN—МХ (М = Li, Na, K,
NH4; X = Br, N3, SCN, NO2) systems. Like manganese
triacetate, CAN is used as initiator of radical addition of
carbonyl compounds to the functionally substituted oleꢀ
fins.5,6 Also CAN revealed unusual catalytic properties in
a number of various reactions, such as esterification of
carboxylic acids with primary and secondary alcohols,7
addition of alcohols to tetrahydropyrane,8 synthesis of
βꢀaminoenones by condensation of amines with βꢀdiꢀ
carbonyl compounds,9 the Michael addition of amines to
α,βꢀunsaturated electrophiles,10 protection of carbonyl
function in form of 1,3ꢀdithianes,11 and removal of acetal
and ketal protections.12
pation of CAN and other CeIV salts were carried out in
solutions of acetonitrile, water, methanol, or acetic acid.
In the present work within the framework of the "green
chemistry" conception, we investigated the solventꢀfree
reactions of CAN. It was found that primary alcohols,
viz., pentanꢀ1ꢀol (1a), heptanꢀ1ꢀol (1b), and nonanꢀ1ꢀol
(1c), being in сontaсt with CAN in a closed reaсtor at
room temperature for 48 h, do not undergo any noticeꢀ
able changes, whereas upon contact with CAN—LiBr sysꢀ
tem for 20 h, they are converted to esters (Scheme 1,
Tables 1 and 2).
Scheme 1
Information on oxidation of alcohols with CeIV salts
goes back to the sixties and seventies. It was found that
primary aliphatic alcohols of >С5 composition upon treatꢀ
ment with CAN were transformed to 2ꢀalkyltetrahydroꢀ
furans,13 whereas 4ꢀphenylbutanꢀ1ꢀol and 5ꢀphenylꢀ
pentanꢀ1ꢀol, to 2ꢀphenylꢀ and 2ꢀbenzyltetrahydroꢀ
furans,14 respectively. Secondary alcohols were oxidized
to ketones or underwent cleavage at С—С(ОН) bond,
giving rise to aldehydes.15 All the reactions with particiꢀ
R = Me (a), Pr (b), nꢀC5H11 (c)
i. CAN—LiBr, 20 °C, solventꢀfree.
When the ratio 1a—c : CAN : LiBr is equal to 1 : 3 : 1,
the conversion of alcohol is ~94—96% and the yield of
esters 2a—c is ~88—91% (see Table 2). A decrease of
relative to 1a—c amounts of CAN or LiBr leads to a
decrease in conversion and, therefore, in the yields of
* Dedicated to Academician V. A. Tartakovsky in honor of his
75th anniversary.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1445—1450, August, 2007.
1066ꢀ5285/07/5608ꢀ1501 © 2007 Springer Science+Business Media, Inc.

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Kapustina et al.
Table 1. Oxidation of heptanꢀ1ꢀol (1b) with CAN—LiBr systema
Entry
Molar ratio
Reaction conditions
Conversion of 1b
Yieldb (%)
1b : CAN : LiBr
(%)
Solvent
t/h
2b
3bc
d
1
2
3
4
5
6 e
7
8 f
9 g
10 g
11 g
1 : 3 : 0
1 : 3 : 0.5
1 : 3 : 1
1 : 2 : 1
1 : 3 : 3
1 : 3 : 1
1 : 3 : 1
1 : 3 : 1
1 : 3 : 3
1 : 3 : 1
1 : 3 : 1
—
—
—
—
48
20
20
20
20
3.5
4
0.5
20
3.5
4
3
78
95
60
96
87
73
81
10
89
65
Traces
69/88
90/95
54/90
88/92
38/44
40/48
59/73
3/3
—
—
—
—
—
41/47
25/34
19/23
—
12/13
10/15
d
d
d
d
—
CH3CN—H2O
H2O
CH3CN—H2O
—
CH3CN—H2O
H2O
73/82
50/77
a 1b, 0.5 mmol; reaction temperature, 20 °С.
b From starting/converted heptanol 1b.
c 2ꢀPropyltetrahydrofuran
d Solventꢀfree.
e 70% aq. CH3CN.
f Reaction temperature, 65 °С.
g Ce(SO4)2•4H2O was used.
Table 2. Solventꢀfree oxidation of alcohols 1а—d with CAN—LiBr systema
Entry
Alcohols 1а—d
C5H11OH (1a)
C7H15OH (1b)
1b
C9H19OH (1c)
С6H13CH(OH)CH3 (1d)
1d
Conversion of 1а—d (%)
Product
Yieldb (%)
1
2
96
96
3
94
80
97
C4H9COOC5H11 (2a)
C6H13COOC7H15 (2b)
C6H13COOC7H15 (2b)
C8H17COOC9H19 (2c)
C6H13COCH3 (4)
88/92
89/93
+
91/97
77/96
3/3
3 c
4
5 c
6 d
C6H13COCH3 (4)
C5H11CH(Br)COCH3 (5)
C6H13COCH2Br (6)
75/77
15/15
a Molar ratio 1 : CAN : LiBr = 1 : 3 : 1; 1, 0.5 mmol; reaction temperature, 20 °C; reaction time, 20 h.
b From starting/converted alcohol 1.
c Molar ratio 1d : CAN = 1 : 3; reaction time, 48 h.
d Molar ratio 1d : CAN : LiBr = 1 : 4 : 1; when ratio is 1 : 3 : 1, the conversion of 1d and the yields of
compounds 5 and 6 decrease.
esters 2a—c (see Table 1). These data suggest that in the
reaction of alcohols with CAN—LiBr system, the generꢀ
ated from LiBr bromine is the active reagent (the characꢀ
teristic color can be seen). Most likely, hemiꢀacetals are
formed from alcohols upon treatment with bromine and
are further oxidized to esters (see Scheme 1).
Another plausible pathway for transformation of
alcohols to esters through the formation of alkanals and
their subsequent oxidation seems to contribute little to
the total balance of the obtained products. This concluꢀ
sion follows from the results of the combined solventꢀfree
oxidation of aldehydes and alcohols with CAN—LiBr sysꢀ
tem at 20 °С. The oxidation of equimolar amounts of
pentanꢀ1ꢀol and heptanal proceeds simultaneously in three
directions to form three esters, viz., pentyl 2ꢀbromoꢀ
heptanoate (7a), pentyl heptanoate (8), and pentyl
pentanоate (2a) in the ratio 5.5 : 0.7 : 1.0. Consequently,
the oxidant is mainly consumed in bromination of
heptanal. The hemiꢀacetal, obtained from the thus formed
2ꢀbromoheptanal by reaction with pentanꢀ1ꢀol, is oxiꢀ
dized to bromo ester 7a (Scheme 2, pathway a; Table 3).
The smaller part of heptanal along the pathway b is conꢀ
verted to hemiꢀacetal and then to the unsymmetrical
ester 8. Pentanꢀ1ꢀol in the presence of heptanal is oxiꢀ
dized slower than heptanal, resulting in the low yield of
symmetrical esters 2a.
We assume that oxidation of aldehyde through the
formation of СеIVꢀoxallylic complex16 with its subseꢀ

Solventꢀfree oxidation of alcohols
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 8, August, 2007
1503
Scheme 2
i. CAN—LiBr; ii. CAN.
Table 3. Solventꢀfree combined oxidation of alcohols 1а, b and heptanal with CAN—LiBr systema
Entry Alcohols
Conversion of (%)
alcohol heptanal
Yield of productsb (%)
2
7
8
1
2 с
3
1a
1a
1b
96
95
90
93
98
91
2a, 13 C5H11CH(Br)COOC5H11 (7a), 72 C6H13COOC5H11 (8), 9
2a, 8
—
8, 80
2b, 18 C5H11CH(Br)COOC7H15 (7b), 74
—
a Molar ratio 1 : heptanal : CAN : LiBr = 1 : 1 : 3 : 1; 1, 1 mmol; reaction temperature, 20 °C; reaction time, 20 h.
b From starting alcohol 1.
c Molar ratio 1а : heptanal : CAN = 1 : 1 : 3.
quent decomposition in the presence of alcohol to the
esters also can not be excluded (Scheme 3).
metrical esters 2a is obtained in insignificant amount, and
ester of 2ꢀbromoheptanoic acid 7a does not virtually form
(see Table 1).
In another similar example of the combined oxidation
of heptanꢀ1ꢀol and heptanal with CAN—LiBr system (see
Table 3, entry 3), heptyl 2ꢀbromoheptanoate (7b) and
heptyl heptanoate (2b) are formed in the ratio 4 : 1 (see
Table 3). Taking into account that symmetrical ester 2b is
formed both by oxidation of alcohol and by oxidation of
aldehyde, it can be considered that this ratio is close
to the ratio of esters, formed by oxidation of heptaꢀ
nal—pentanꢀ1ꢀol pair.
Scheme 3
These data on the combined oxidation of alkanꢀ1ꢀ
ol/alkanal pair with CAN—LiBr system serve as a deciꢀ
sive argument in favor of the shown in Scheme 1 mechaꢀ
nism. This Scheme excludes the participation of alkanal
as the main intermediate product in the oxidation proꢀ
cess. Otherwise, αꢀbromo esters would have been preꢀ
sented among the reaction products, however, they were
not detected.
The combined oxidation of heptanal and pentanꢀ1ꢀol
with CAN without additives of LiBr (see Table 3, entry 2)
leads mainly to unsymmetrical ester 8, while the symꢀ

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Kapustina et al.
This result is interesting for the comparison of
CAN—LiBr system with Pb(OAc)4—LiBr (NaCl)17 and
Oxone—NaCl18 oxidation systems, which also convert
alkanꢀ1ꢀols to esters, only, as the authors suggested,
through the formation of aldehydes.
In contrast to primary alcohols, secondary octanꢀ2ꢀol
(1d) is easily oxidized to octanꢀ2ꢀone (4) upon the solꢀ
ventꢀfree contact with CAN. In the CAN—LiBr system,
the oxidation proceeds in two steps: the formed in the first
step ketone 4 is further brominated by the generated from
LiBr bromine. According to 1H NMR and chromatoꢀ
mass spectrometry data, if ratio of reagents is 1 : 4 : 1,
then 3ꢀbromooctanꢀ2ꢀone (5), 1ꢀbromooctanꢀ2ꢀone (6),
and a small amount of octanꢀ2ꢀone are obtained
(Scheme 4, see Table 2).
with CAN—LiBr system, their oxidation to 2ꢀalkyltetraꢀ
hydrofurans by CAN without LiBr participation takes
place (Scheme 5).
The freeꢀradical pathway of oxidation of alkanols,
given in Scheme 5, has been postulated earlier,15 but till
now it was not experimentally confirmed. We were able to
register the formation of radicals during oxidation of 1b
with ceric sulfate (CS) in the presence of the spin trapping
agent, СꢀphenylꢀNꢀtertꢀbutylnitrone (PBN). In the ESR
spectrum, there were two triplets of doublets: one with
αN = 13.7, αβꢀH = 2.1 Gs, g = 2.0060, corresponding to
the spinꢀadduct of alkoxyl radicals with PBN, and anꢀ
other one with αN = 14.4, αβꢀH = 3.4 Gs, g = 2.0062,
characteristic of the spinꢀadduct of carbonꢀcentered
radicals with PBN.19 In this case, the carbonꢀcentered
radicals, obviously, have the •C(Pr)H(CH2)3OH strucꢀ
ture, since exactly these radicals are the precursors
of 2ꢀpropyltetrahydrofuran (3b), formed according to
Scheme 5.
The choice of CS instead of CAN is caused by the
high chemical activity of CAN, upon reaction of which
with the spin trapping agents, such as PBN, 2ꢀmethylꢀ2ꢀ
nitrosopropane (MNP), and nitrosodurene (ND), in the
absence of alcohols, the signals of nitroxyl radicals were
observed in the ESR spectra. The similar picture appeared
for the combination of CS with MNP and ND, and only
As one can see, the participation of LiBr in oxidation
process again increases the conversion of 1d and the total
yield of products 4, 5, and 6.
To compare the solventꢀfree reaction and reaction in
solution of alcohols with CAN—LiBr, the oxidation of
alcohol 1b in CH3CN—H2O or in H2O at 20 °С was
carried out. The conversion of 1b for 4 h was 83—87%,
the yield of ester 2b was ~40%. At the same time, 2ꢀpropylꢀ
tetrahydrofuran (3b) was formed in about the same yield
(see Table 1). Thus, there are two parallel processes in
solution: along with the oxidation of alcohols to esters
Scheme 4
i. CAN; ii. CAN—LiBr.
Scheme 5
Reagents and conditions: CAN—LiBr, 20 °С, in CH3CN—H2O.

Solventꢀfree oxidation of alcohols
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 8, August, 2007
1505
thoroughly mulled in air in a porcelain mortar for 5—10 min,
then it was placed in a glass flask, which was then tightly capped,
and kept for 20 h at 20 °С until complete conversion of CAN.
After the reaction was over (the orange color of reaction mixture
turned pale yellow), water (10—15 mL) was added and this
was extracted with ether (3×20 mL). The combined extract
was washed with saturated aq. NaHCO3 (10—15 mL), water
(10—15 mL) and dried with MgSO4. After removal of the
volatiles, the conversion of the starting alcohols and the yields of
the reaction products were determined by GLC with the use of
the internal standard. Structures of the synthesized compounds
were established by 1Н and 13С NMR and chromatoꢀmass specꢀ
trometry, IR spectroscopy, elemental analysis data, and by comꢀ
parison with authentic samples.
Oxidation of heptanꢀ1ꢀol (1b) with CAN—LiBr system in
СН3CN—H2O (or Н2О). A mixture of 1b (1 mmol), CAN
(3 mmol), and LiBr (1 mmol) in 70% aq. CH3CN (20 mL) was
vigorously stirred at ~20 °С until complete conversion of the
oxidant for 3.5—4 h. Then this was extracted with ether
(3 × 25 mL), the extracts were washed with saturated
aq. NaHCO3 and water, dried with MgSO4 and the solvent was
evaporated. The yield of the reaction products and conversion of
the alcohol were determined by GLC (see Table 1).
for PBN—CS system, no signals of paramagnetic species
were registered. Therefore, this system was used for deterꢀ
mining of the mechanism of alcohols oxidation with
СеIV salts.
Such an approach to the choice of CS is fully justified,
since, as it was established, CS does not in principal differ
from CAN in the reaction with alcohols. Indeed, the
solventꢀfree oxidation of alcohol 1b with CS—LiBr sysꢀ
tem gave a small amount of ester 2b (3%), while the
oxidation in CH3CN—H2O (or Н2О) afforded two prodꢀ
ucts, viz., ester 2b and 2ꢀpropyltetrahydrofuran (3b), in
the ratio 6 : 1 and total yield 85%, i.е., the oxidation
process with participation of CAN—LiBr or CS—LiBr
systems can be alike presented by Schemes 1 and 5.
In the conclusion, the solventꢀfree oxidation of alkanꢀ
1ꢀols with CAN—LiBr system proceeds with participaꢀ
tion of the generated from LiBr bromine and leads to
esters, the acid and alcohol parts of which are formed
from the starting compounds. The reaction can be used
for the preparative synthesis of esters.
Oxidation of heptanꢀ1ꢀol (1b) with CS—LiBr system. The
solventꢀfree reaction and reaction in CH3CN—H2O (or H2O)
were carried out similarly to the procedures with the use of
CAN—LiBr (see Table 1).
Solventꢀfree combined oxidation of alcohols 1a,b and heptanal
with CAN—LiBr system (general procedure). A mixture of alcoꢀ
hol (1 mmol), heptanal (1 mmol), CAN (3 mmol), and LiBr
(1 mmol) was mulled in a porcelain mortar, kept for 20 h in a
capped glass flask until complete conversion of CAN, and this
was treated according to the aforementioned procedure (see
Table 3).
Experimental
GLC analysis was performed on a Chromꢀ5 chromatograph
with the flameꢀionization detector and 3 m × 3 mm analytical
glass column with 5% SEꢀ30 and 5% FFAP on Chromaton
NꢀAWꢀHMDS (0.16—0.20 mm) (with heptanꢀ2ꢀone as the inꢀ
ternal standard). The product yields were determined by the
internal standard method with the experimentally found correcꢀ
tion factors. IR spectra were recorded on a Perkin—Elmer 577
1
spectrophotometer for neat samples. Н and 13С NMR spectra
were recorded on a Bruker ACꢀ200 spectrometer in СDСl3 unꢀ
der standard conditions, chromato mass spectra were recorded
on a Finigan MAT ITDꢀ700 spectrometer (electron ionization,
70 eV, the source of ions — ions trap system temperature,
220 °С) and Carlo Erba 4200 chromatograph, provided with
25 m × 0.2 mm Ultraꢀ1 column (Hewlett—Packard), the staꢀ
tionary phase (polymethylsiloxane) film thickness, 0.33 m, carꢀ
rier gas, helium. ESR spectra were recorded on a VarianꢀE12
radiospectrometer. The starting primary alcohols (pentanꢀ1ꢀ
ol (1a), heptanꢀ1ꢀol (1b), and nonanꢀ1ꢀol (1с)) and secondary
octanꢀ2ꢀol (1d) were purchased from Acros and redistilled beꢀ
fore use. Ceric ammonium nitrate (Сe(NH4)2(NO3)6) and ceric
sulfate (Ce(SO4)2×4H2O), the pure for analysis reagents (Acros),
were used without additional purification. Acetonitrile, pure
reagent grade (Acros) was redistilled before use. Commercial
lithium bromide was dried in a drying oven before use.
ESR spectra were recorded during oxidation of heptanꢀ1ꢀol
(1b) with ceric sulfate in the presence of СꢀphenylꢀNꢀtertꢀ
butylnitrone as the spin trapping agent. Ceric sulfate and soluꢀ
tion of alcohol with PBN (0.05 mol L–1) were placed in a glass
cylindrical tube (with internal diameter ~3 mm). The tube was
degassed by a few cycles of freezingꢀevacuationꢀthawing, sealed
in vacuo and placed in the spectrometer resonator. The spectra
were registered at ~20 °C.
nꢀPentyl pentanoate (2a). IR, ν/cm–1: 1728 (О—С=О). MS,
m/z: 173 [M + H]+. 1Н and 13С spectra agree with the described
earlier ones.18
nꢀHeptyl heptanoate (2b) (see Ref. 20). IR, ν/cm–1: 1740
(О—С=О). 1Н NMR (CDCl3), δ: 0.85 (t, 6 Н, СН3, J = 6.4 Hz);
1.32 (m, 14 Н, СН2); 1.57 (m, 4 Н, СН2); 2.25 (t, 2 Н,
СН2СОО, J = 7.3 Hz); 4.01 (t, 2 Н, СН2ОСО, J = 6.5 Hz).
13С NMR (CDCl3), δ: 13.85 (СН3); 21.89, 22.45, 24.83, 25.79,
25.87, 28.65, 29.97, 30.98, 31.70 (СН2); 35.01 (СН2СОО); 65.21
(СН2ОСО); 173.34 (С=О). MS, m/z: 229 [M + H]+.
nꢀNonyl nonanoate (2с) (see Ref. 21). IR, ν/cm–1: 1740
(О—С=О). 1Н NMR (CDCl3), δ: 0.88 (t, 6 Н, СН3, J = 6.4 Hz);
1.27 (m, 24 Н, СН2); 1.61 (m, 2 Н, СН2); 2.29 (t, 2 Н,
СН2СОО, J = 7.2 Hz); 4.05 (t, 2 Н, СН2ОСО, J = 6.5 Hz).
13С NMR (CDCl3), δ: 14.08 (СН3); 21.94, 22.50, 22.64, 24.77,
24.83, 25.01, 25.97, 28.63, 29.02, 29.14, 29.23, 29.47, 31.81
(СН2); 34.39 (СН2СОО); 64.38 (СН2ОСО), 174.02 (С=О).
MS, m/z: 285 [M + H]+.
2ꢀPropyltetrahydrofuran (3d) (see Ref. 16). 1Н NMR
(CDCl3), δ: 0.87 (t, 3 Н, СН3, J = 7.0 Hz); 1.45 (m, 4 Н, СН2);
1.55 (m, 2 Н, СН2(3)); 1.80 (m, 2 Н, СН2(4)); 3.65 (m, 3 Н,
С(5)Н2, C(2)H).
Octanꢀ2ꢀоne (4). IR, ν/cm–1: 1716 (С=О). 1Н and 13С NMR
spectra agreed with the described earlier ones.18
Solventꢀfree oxidation of alcohols (1a—d) with CAN—LiBr
system (general procedure). A mixture of alcohols 1a—d, CAN
and LiBr (ratios of reagents are given in Tables 1 and 2) was
3ꢀBromooctanꢀ2ꢀone (5) (see Ref. 22). 1Н NMR (CDCl3),
δ: 0.87 (t, 3 Н, СН3, J = 6.4 Hz); 1.28 (m, 4 Н, СН2); 1.62, 1.97
(both m, 2 Н each, СН2); 2.34 (s, 3 Н, СН3СО); 4.22 (m, 1 Н,

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Russ.Chem.Bull., Int.Ed., Vol. 56, No. 8, August, 2007
Kapustina et al.
СНBrCO). 13С NMR (CDCl3), δ: 14.05 (CH3); 25.87 (CH3CO);
4. R. H. Tale, Org. Lett., 2002, 4, 1641.
22.37, 28.99, 31.14, 33.36 (CH2); 54.87 (CHBr); 201.78 (C=O).
5. A. Szummy and C. Wawrzenczyk, Synlett, 2006, 1523.
6. W. Chen, X. Huang, H. Zhou, and L. Ren, Synthesis,
2006, 609.
7. W.ꢀB. Pan, F.ꢀR. Chang, L.ꢀM. Wei, M.ꢀJ. Wu, and
Y.ꢀC. Wu, Tetrahedron Lett., 2003, 44, 331.
8. K. Pachamuthu and Y. D. Vankar, J. Chem. Soc., 2001,
66, 7511.
9. Z. Duan, X. Xuan, T. Li, C. Yang, and Y. Wu, Tetrahedron
Lett., 2006, 47, 5433.
10. V. S. Sridharan, C. Avendano, and J. C. Menendez, Synlett,
2007, 881.
11. G. Maiti and Ch. Roy, Synth. Comm., 2002, 32, 2269.
12. I. E. Marko, A. Ates, A. Gautier, B. Leory, J. M. Pluncher,
Y. Quesnel, and J. Vanherk, Angew. Chem., Int. Ed., 1999,
38, 3207.
13. W. S. Trahanovsky, M. G. Young, and P. M. Nave, Tetraꢀ
hedron Lett., 1962, 2501.
MS, m/z: 209 [M + H]+ 81Br); 207 [M + H]+ 79Br).
( (
1ꢀBromooctanꢀ2ꢀone (6) (see Ref. 22). 1Н NMR (CDCl3),
δ: 0.87 (t, 3 Н, СН3, J = 6.4 Hz); 1.40 (m, 8 Н, СН2); 2.58 (t,
2 Н, СН2СО, J = 7.1 Hz); 3.88 (s, 2 Н, СН2Br). 13С NMR
(CDCl3), δ: 13.98 (CH3); 22.36, 23.30, 27.99, 31.40 (CH2);
33.70 (CH2Br); 42.56 (CH2CO); 200.08 (C=O). MS, m/z: 209
[M + H]+
(
81Br); 207 [M + H]+
(
79Br).
Pentyl 2ꢀbromoheptanoate (7a). Found (%): С, 51.61;
H, 8.24; Br, 28.67. C12H23O2Br. Calculated (%): С, 51.10;
H, 8.66; Br, 28.30. 1Н NMR (CDCl3), δ: 0.91 (t, 6 Н, СН3, J =
6.4 Hz); 1.31 (m, 8 Н, СН2); 1.62 (m, 4 Н, СН2); 1.97 (m, 2 Н,
СН2СHBr); 4.04 (t, 2 Н, СН2ОСО, J = 6.3 Hz); 4.19 (m, 1 Н,
СНBr). 13С NMR (CDCl3), δ: 13.98 (CH3); 22.55, 23.11,
27.67, 27.89, 28.64, 35.01, 39.23 (CH2); 45.27 (CHBr); 64.33
(СН2ОСО); 172.02 (С=О). MS, m/z: 281 [M + H]+
[M + H]+ 79Br).
(
81Br); 279
(
Heptyl 2ꢀbromoheptanoate (7b). Found (%): С, 54.72;
H, 8.79; Br, 26.06. C14H27O2Br. Calculated (%): С, 54.98;
H, 9.10; Br, 26.35. 1Н NMR (CDCl3), δ: 0.89 (t, 6 Н, СН3, J =
6.4 Hz); 1.27 (m, 12 Н, СН2); 1.61 (m, 4 Н, СН2); 2.10 (m,
2 Н, СН2СHBr); 3.97 (t, 2 Н, СН2ОСО, J = 6.5 Hz); 4.13 (m,
1 Н, CHBr). 13С NMR (CDCl3), δ: 14.08 (CH3), 22.78, 23.15,
25.64, 27.90, 28.59, 32.23, 33.01, 34.99, 39.85 (CH2), 45.00
(CHBr), 64.01 (СН2ОСО), 171.77 (С=О). MS, m/z: 309
14. M. P. Doyle, L. S. Zuidema, and T. R. Bade, J. Chem. Soc.,
1975, 40, 1454.
15. W. S. Trahanovsky, in Methods in FreeꢀRadical Chemistry,
Ed. E. S. Huyser, Marcel Dekker, New York, 1973,
vol. 4, 133.
16. M. G. Vinogradov, I. P. Kovalev, and G. I. Nikishin, Usp.
Khim., 1986, 55, 1979 [Russ. Chem. Rev., 1986, 55, 1130
(Engl. Transl.)].
17. N. I. Kapustina, L. L. Sokova, V. D. Makhaev, A. P. Borisov,
and G. I. Nikishin, Izv. Akad. Nauk, Ser. Khim., 2000, 1870
[Russ. Chem. Bull., Int. Ed., 2000, 49, 1842].
18. A. Schulz, G. Pagona, and A. Giannis, Synth. Commun.,
2006, 36, 1147.
19. N. I. Kapustina, A. V. Lisitsyn, and G. I. Nikishin, Izv.
Akad. Nauk SSSR, Ser. Khim., 1989, 98 [Bull. Acad. Sci.
USSR, Div. Chem. Sci., 1989, 38, 86 (Engl. Transl.)].
20. R. Bilterys and J. Gisseleire, Bull. Soc. Chim. Belg., 1935,
44, 574.
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Chem., 1997, 33, 453 (Engl. Transl.)].
[M + H]+
(
81Br); 307 [M + H]+
(
79Br).
nꢀPentyl heptanoate (8) (see Ref. 20). IR, ν/cm–1: 1735
(О—С=О). 1Н NMR (CDCl3), δ: 0.89 (t, 6 Н, СН3, J = 6.4 Hz);
1.30 (m, 10 Н, СН2); 1.66 (m, 4 Н, СН2); 2.28 (t, 2 Н,
СН2СОО, J = 7.1 Hz); 3.99 (t, 2 Н, СН2ОСО, J = 6.4 Hz).
MS, m/z: 201 [M + H]+.
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 06ꢀ03ꢀ
32579а) and by the Russian Federation President Council
for Grants (Program for the State Support of Leading
Scientific Schools, Grant No. 5022.2006.3).
22. S. I. Zav´yalov, G. I. Ezhova, I. V. Sitkareva, O. V.
Dorofeeva, A. G. Zavozin, and E. E. Rumyantseva, Izv.
Akad. Nauk SSSR, Ser. Khim., 1989, 2392 [Bull. Acad. Sci.
USSR, Div. Chem. Sci., 1989, 38, 2204 (Engl. Transl.)].
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Received April 25, 2007;
in revised form June 28, 2007