Reductive ethylation of homoallyl alcohols with a disubstituted double bond with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide

Article abstract of DOI:10.1134/S1070428006050034

Homoallyl and bishomoallyl alcohols with a disubstituted double bond treated with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide are converted into the products of a reductive ethylation of the olefin fragment. Under similar conditions esters of β,γ-unsaturated carboxylic acids undergo a successive cyclopropanation of the ester group and reductive ethylation of the double carbon-carbon bond and yield 1-(3-ethylalkyl)cyclopropanols. The features of the observed reactions are explained in the framework of the carbometallation mechanism of the double carbon-carbon bond by the action of dialkoxytitanacyclopropane reagents. Pleiades Publishing, Inc. 2006.

Full text of DOI:10.1134/S1070428006050034

ISSN 1070-4280 Russian Journal of Organic Chemistry, 2006, Vol. 42, No. 5, pp. 659-664. Ó Pleiades Publishing, Inc. 2006.
Original Russian Text Ó O.G. Kulinkovich, T.A. Shevchuk, V.E. Isakov, K.N. Prokhorevich, 2006, published in Zhurnal Organicheskoi Khimii,
2006, Vol. 42, No. 5, pp. 679-684.
Reductive Ethylation of Homoallyl Alcohols
with a Disubstituted Double Bond with Ethylmagnesium Bromide
in the Presence of Titanium(IV) Isopropoxide
O.G. Kulinkovich, T.A. Shevchuk, V.E. Isakov, and K.N. Prokhorevich
Belarussian State University, Minsk, 220050 Belarus
e-mail: kulinkovich@bsu.by
Received March 16, 2005
Abstract—Homoallyl and bishomoallyl alcohols with a disubstituted double bond treated with ethylmagnesium
bromide in the presence of titanium(IV) isopropoxide are converted into the products of a reductive ethylation of
the olefin fragment. Under similar conditions esters of b,g-unsaturated carboxylic acids undergo a successive
cyclopropanation of the ester group and reductive ethylation of the double carbon–carbon bond and yield 1-(3-
ethylalkyl)cyclopropanols. The features of the observed reactions are explained in the framework of the
carbometallation mechanism of the double carbon–carbon bond by the action of dialkoxytitanacyclopropane
reagents.
DOI: 10.1134/S1070428006050034
The reaction of titanium(IV) isopropoxide with ethyl-
magnesium bromide proceeds through a stage of diethyl-
diisopropoxytitanium which under common conditions
suffers disproportionation into ethane and a labile diiso-
propoxytitanacyclopropane (I) [1] (Scheme 1). Reagent
I is capable of behaving as an equivalent of a 1,2-di-
carbanion in reactions with derivatives of carboxylic acids
and some other electrophilic substrates, or it acts as
an equivalent of an ethyl carbanion [2]. Thus reagent I
generated in situ transformed the esters of carboxylic
acids into 1-substituted cyclopropanols [1], whereas allyl
alcohols under similar conditions suffered SN2' substitution
of the hydroxyl by an ethyl group [3]. The latter process
is an analog of olefins carbomethallation (Dzhemilev
reaction) [4], and it occurs through generation of the
corresponding titanacyclopentane intermediates [3, 5].
ligand exchange with olefins [6]. In reactions with
homoallyl and bishomoallyl alcohols with a terminal double
bond these processes induce formation of products of
the substrate reductive dimerization by the “head-to-head”
type [7]. We report here on the alternative route of the
reaction between titanacyclopropane reagents I with
homoallyl IIa and IIb and bishomoallyl IIc–IIe alcohols
with a disubstituted double bond.
The addition of 4 equiv of ethylmagnesium bromide to
an ether solution of equimolar quantities of compounds
IIa–IIe and titanium(IV) isopropoxide at room tempera-
ture afforded as the main products mixtures of saturated
and unsaturated monohydric alcohols (see the table) that
were separated from the other components of the reaction
mixture by column chromatography. According to the
NMR and GC=MS data the isolated fractions of mono-
hydric alcohols with the close values of the chromato-
graphic mobility contained from 66 to 98% of the product
of reductive ethylation of the double carbon-carbon bond
IIIa–IIIe (Scheme 2).
Titanacyclopropane I is also able to show the property
of a titanium-ethylene complex and can take part in the
Scheme 1.
The application of relatively large amounts of ethyl-
magnesium bromide and titanium(IV) isopropoxide some-
what increased the yield of ethylation products, but
therewith the substrate conversion did not notably grow
(see table, runs nos. 3–5, 7, 9). Even in reaction of
tertiary alcohol IIb with 10 equiv of ethylmagnesium
8 C
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659

KULINKOVICH et al.
660
Scheme 2.
bromide and 3 equiv of titanium(IV) isopropoxide about
15% of the initial compounds was recovered unchanged
(run no. 5). The variation of concentration of the reactants
and of reaction temperature also did not significantly
raised the yield of compound IIIb or the conversion of
the substrate. At the same time primary alcohol IIa and
secondary alcohol IId under the given conditions were
nearly totally consumed (runs nos. 1, 8), but significant
amounts of side products of low chromatographic mobility
were obtained.
Considering the above mentioned ability of reagent I
to convert esters of carboxylic acids into 1-substituted
cyclopropanols [1] we studied also the reactions of
ethylmagnesium bromide and titanium(IV) isopropoxide
with esters of b,g-unsaturated carboxylic acids IVa–IVd.
The treatment of esters IVa–IVd with 6 equiv of
ethylmagnesium bromide and 1.7 equiv of titanium(IV)
isopropoxide afforded in 82–88% yields the corresponding
saturated cyclopropanols Va–Vd (Scheme 3). Under the
applied reaction conditions a complete conversion of
alkenoates IVa–IVd was observed, and the yields of
compounds Va–Vd originating from a two-stage process
of ester group cyclopropanation and reductive ethylation
of the double carbon-carbon bond were to our surprise
considerably higher than those of the products of the one-
stage reductive ethylation of tertiary unsaturated alcohols
n = 1, R = R' = H a(), CH3 (b); n = 2, R = R' = H c(), CH3 (e);
R = H, R' = CH3 (d).
Scheme 3.
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5
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IIb and IIe.
R = CH3 (a), C2H5 (b), C3H7 (c), C5H11 (d).
Decreasing the relative amount of titanium(IV) iso-
propoxide from 1.7 to 1.3 equiv in the reaction of com-
pound IVb with 6 equiv of ethylmagnesium bromide
resulted in formation in a 62% yield of a mixture of 1-(3-
ethylpentyl)cyclopropanol Vb and 1-(3-pentenyl)cyclo-
propanol VIb in a ratio 85:15. Compound VI turned out
to be the main product in reaction of ester IVb with
2 equiv of ethylmagnesium bromide in the presence of
1 equiv of titanium(IV) isopropoxide; therewith we failed
to detect in the reaction mixture any products of the double
carbon-carbon bond alkylation in compound IVb which
retained the ester function (Scheme 4). These data
indicate the comparable activity of titanacyclopropane I
with respect to the ester group of compounds IV and the
double carbon-carbon bond of alkenylcyclopropanols VI.
At the same time we did not find any notable amounts of
products originating from the reductive ethylation of the
double carbon-carbon bond in a reaction of methyl oleate
(VII) with ethylmagnesium bromide in the presence of
titanium(IV) isopropoxide under standard conditions: The
only product isolated from the reaction mixture was
unsaturated cyclopropanol VIII (Scheme 4). The
Conversion of unsaturated alcohols II and yield of reductive
ethylation products III in reaction with ethylmagnesium
bromide in the presence of titanium(IV) isopropoxide
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1H NMR spectra of the reaction mixture.
b Yield calculated on the reacted alkenol II.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 42 No. 5 2006

REDUCTIVE ETHYLATION OF HOMOALLYL ALCOHOLS
661
Scheme 4.
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lates A (at m > 1) where a higher rate of conversion into
intermediates D should be expected.
retention of the multiple bond in compound VIII was not
obviously due to its cis-configuration, but to the remote
position of the hydroxy and olefin groups, since a special
experiment of cyclopropanation under the same conditions
of a cis-trans isomer mixture of compound IVb (cis:trans
ratio was 60:40) gave the saturated cyclopropanol Vb in
a high yield.
When the reaction mixture prepared under above
described conditions from compound I and substrate IVa
was treated with DCl in D2O formed 1-(2,5-dideutero-3-
methylpentyl)cyclopropanol (Va-D). This fact is in
agreement with the assumption that the reaction proceeds
via titanacyclopentane intermediates C. The deuterium
content in positions 2 and 5 of compound Va-D, and also
in the product obtained thereof by an acid-catalyzed ring
The experimental data obtained may be interpreted in
the framework of the mechanism we have previously
suggested of allyl ethylation [3] and reductive coupling
of unsaturated alcohols under the action of dialkoxytitana-
cyclopropane reagents [7]. Titanium alcoholates A origin-
ating from the trans-etherification of the titanium(IV)
isopropoxide (we do not consider for the sake of simplicity
the possible participation in the reactions of the magnesium
alcoholates) treated with ethylmagnesium bromide are
converted into the corresponding titanacyclopropane
derivatives B (Scheme 5). The addition to the latter of
ethylmagnesium bromide induces [5] the formation of
titanacyclopentane at-complexes C which are the direct
precursors of compounds III and V. We believe that the
easier occurrence of the reductive ethylation of the
1-alkenyl-substituted cyclopropanolates A (R1 + R2 =
CH2CH2) is caused by the enhanced values of the bond
angles between the geminal exocyclic bonds in the
cyclopropane compounds [8]. These differences may
stabilize cyclopropane-containing at-complexes C (R1 +
R2 = CH2CH2) owing to the reduced internal strain in the
oxatitanacyclopentane ring and may destabilize the leading
to side products titanium-olefin complexes D by
hampering the coordination of the multiple bond to the
metal. In its turn the observed growing yields of reductive
ethylation products in the presence of excess titanium(IV)
isopropoxide is due to the increased equilibrium concentr-
ation of monoalkenyl cyclopropanolates A (at m = 1)
compared with those formed at the deeper trans-
etherification of titanium(IV) isopropoxide with alcoho-
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 42 No. 5 2006

KULINKOVICH et al.
662
Scheme 6.
compounds under study in CDCl3 using TMS as internal
reference on spectrometers Bruker AvanCe-400 at
operating frequencies 400 (1H), 100 MHz (13C), and
Brucker AC-200 at operating frequency 200 MHz (1H).
GC-MS measurements were performed on a Hewlett
Packard GC MS 5890/5972 instrument (electron impact
energy 70 eV).
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Reductive ethylation of unsaturated alcohols IIa–
IIe with ethylmagnesium bromide in the presence
of titanium(IV) isopropoxide. To a stirred solution of
2.5 mmol of unsaturated alcohol II and 2.5–5.0 mmol of
Ti(OPr-i)4 in 7–15 ml of anhydrous ethyl ether was added
within 0.5 h 10–17.5 mmol of EtMgBr as a 1.0–1.4 M
solution in the same solvent. On completion of the addition
the reaction mixture was stirred for 0.5 h and then was
treated with 10% H2SO4 at 0°C. The organic layer was
separated, the reaction products from the water layer
were extracted into ether (4´10 ml). The combined ether
solutions were washed in succession with saturated
solutions of NaHCO3 and NaCl, dried with MgSO4,
evaporated, and the residue was subjected to column
chromatography on silica gel (eluent petroleum ether–
dichloromethane). The yields of compounds were estimat-
ed from the ratio of the integral intensity of the upfield
signals of methyl groups and of the areas of the
chromatographic peaks. The spectral characteristics of
compounds IIIa and IIIc (content in the isolated fractions
about 70%) were consistent with those published in [11,
12].
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opening, 5,8-dideutero-6-methyloctan-3-one (IX-D),
exceeded 95% according to the data of 1H NMR spectro-
scopy (Scheme 6).
The involvement of complex B into the concurrent
process of the ethylene ligand displacement with titanium
alcoholates A present in excess in the initial stages of the
ethylation furnishes titanium(II)-bisolefin complexes D
which add ethylmagnesium bromide to transform into
tricyclic titanacyclopentane at-complexes E. The
hydrolytic cleavage of intermediates D and E at the
workup of the reaction mixture leads respectively to
recovery of initial unsaturated alcohols II and to formation
of the products of their reductive coupling. The latter
process prevails in reactions of homoallyl alcohols with
the less sterically hindered terminal double bond [7]. Thus
complexes D can play the role of certain vessels for
conservation of alkoholates of the unsaturated alcohols;
this fact explains the unsuccessful attempts to increase
the conversion of initial compounds II even at application
of a considerable excess of organometallic reagents (see
above).
2,5-Dimethylheptan-2-ol (IIIb) (content in the
–1
isolated fraction 98%). IR spectrum, cm : 3609, 3453.
1H NMR spectrum (400 MHz), d, ppm: 0.81 t (3H,
J 7.3 Hz), 0.81 d (3H, J 6.4 Hz), 1.03–1.48 m (7H),
1.14 s (6H), 1.84 br.s (1H). 13C NMR spectrum
(100 MHz), d, ppm: 11.19, 19.06, 29.06, 29.27, 30.82,
34.72, 41.22, 70.91. Mass spectrum, m/z: 29, 43, 55, 59
(100%), 69, 74, 81, 85, 91, 97, 111, 125, 129.
Considering the ability of cyclopropanols to opening
of the three-membered ring under mild conditions [9] the
approach developed in this study to preparation of these
compounds with a branched carbon-carbon skeleton from
the esters of b,g-unsaturated acids may be of interest
from synthetic viewpoint. In particular, nondeuterated 6-
methyloctan-3-one (IX) is a component of the anxiety
pheromone of ants from the Genus Crema-togaster
[10].
6-Methyloctan-2-ol (IIId) (content in the isolated
–1
fraction 74%). IR spectrum, cm : 3613, 3393. 1H NMR
spectrum (400 MHz), d, ppm: 0.82 d (3H, J 6.4 Hz),
0.82 t (3H, J 7.1 Hz), 1.02–1.18 m (2H), 1.14 d (3H,
J 6.1 Hz ), 1.18–1.61 m (7H), 2.07 br.s (1H), 3.75 sextet
(1H, J 5.7 Hz). 13
C NMR spectrum (100 MHz), d, ppm:
11.25, 19.05, 23.17, 23.32, 29.35, 34.30, 36.52, 39.61,
68.00. Mass spectrum, m/z: 29, 45 (100%), 55, 69, 84, 97,
111, 129, 143 [M – 1]+.
EXPERIMENTAL
IR spectra were recorded on a spectrophotometer
Specord 75IR from solutions in CCl4. 1H and 13C NMR
spectra were registered from 5–10% solutions of
2,6-Dimethyloctan-2-ol (IIIe) (content in the isolat-
–1
ed fraction 82%). IR spectrum, cm : 3607, 3400. 1H NMR
spectrum (400 MHz), d, ppm: 0.82 d (3H, J 6.4 Hz),
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 42 No. 5 2006

REDUCTIVE ETHYLATION OF HOMOALLYL ALCOHOLS
663
0.82 t (3H, J 7.2 Hz), 1.00–1.43 m (9H), 1.16 s (6H),
1.79 br.s (1H). 13C NMR spectrum (100 MHz), d, ppm:
11.27, 19.08, 21.75, 29.06, 29.39, 34.32, 37.07, 44.22,
71.00. Mass spectrum, m/z: 29, 43, 59 (100%), 69, 83, 95,
102, 111, 125, 143.
1-(3-Ethylhexyl)cyclopropanol (Vc). Yield 87%. IR
–1
1
spectrum, cm : 3595, 3075. H NMR spectrum
(400 MHz), d, ppm: 0.43 d.d (2H, J1 6.3, J2 5.1 Hz),
0.73 d.d (2H, J1 6.3, J2 5.1 Hz), 0.84 t (3H, J 7.4 Hz),
0.88 t (3H, J 6.6 Hz), 1.17–1.33 m (7H), 1.41–1.55 m
(4H), 1.73 br.s (1H). 13C NMR spectrum (100 MHz), d,
ppm: 10.76, 13.40, 14.42, 19.79, 25.84, 29.01, 35.30, 35.53,
38.50, 56.01. Found, %: C 77.09; H 12.75. C11H22O.
Calculated, %: C 77.58; H 13.02.
1-(3-Ethylalkyl)-substituted cyclopropanol from
esters of 3-alkenoic acids IVa–IVd. To a stirred
solution of 10 mmol of 3-alkenoate and 17 mmol of
Ti(OPr-i)4 in 30 ml of anhydrous ethyl ether was added
within 2 h 60 mmol of EtMgBr as a 1M solution in the
same solvent. On completion of the addition the reaction
mixture was stirred for 0.5 h and then was treated with
5% H2SO4 at 0°C. The products were extracted from
the water layer into ether (3´30 ml). The combined ether
solutions were washed in succession with saturated
solutions of NaHCO3 and NaCl, dried with MgSO4,
evaporated, and the residue was subjected to column
chromatography on silica gel to isolate compounds Va–
Vd (eluent cyclohexane– ethyl acetate).
1-(3-Ethyloctyl)cyclopropanol (Vd). Yield 87%. IR
–1
1
spectrum, cm : 3595, 3073. H NMR spectrum (400
MHz), d, ppm: 0.43 d.d (2H, J1 6.0, J2 5.0 Hz), 0.73 d.d
(2H, J1 6.0, J2 5.0 Hz), 0.84 t (3H, J 7.0 Hz), 0.88 t (3H,
J 6.8 Hz), 1.17–1.34 m (11H), 1.40–1.55 m (4H),
1.80 br.s (1H). 13C NMR spectrum (100 MHz), d, ppm:
10.75, 13.32, 14.03, 22.64, 25.78, 26.32, 29.00, 32.29,
33.04, 35.28, 38.72, 55.91. Found, %: C 78.44; H 12.88.
C13H26O. Calculated, %: C 78.72; H 13.21.
1-(2-Pentenyl)cyclopropanol (VI) containing 15%
of compound Vb was obtained by the similar procedure
from ethyl 3-hexenoate using 6 equiv of EtMgBr and
1-(3-Methylpentyl)cyclopropanol (Va). Yield 88%.
–1
IR spectrum, cm : 3593, 3073. 1H NMR spectrum (400
–1
0.2 equiv of Ti(OPr-i)4. Yield 61%. IR spectrum, cm :
MHz), d, ppm: 0.44 d.d (2H, J1 6.0, J2 4.5 Hz), 0.74 d.d
(2H, J1 6.0, J2 4.5 Hz), 0.87 d (3H, J 5.5 Hz), 0.88 t (3H,
J 7.0 Hz), 1.08–1.20 m (1H), 1.22–1.40 m (3H), 1.42–
1.58 m (3H), 1.87 br.s (1H). 13C NMR spectrum
(100 MHz), d, ppm: 11.29, 13.39, 13.48, 19.15, 29.40,
32.49, 34.33, 35.75, 56.00. Mass spectrum, m/z: 27, 29,
41, 43 (100%), 55, 57, 72, 85, 95, 142 [M]+. Found, %:
C 75.62; H 12.35. C9H18O. Calculated, %: C 76.00;
H 12.76.
3580, 3066, 1466. 1H NMR spectrum (200 MHz), d, ppm:
0.50 d.d (2H, J1 7.0, J2 5.0 Hz), 0.76 d.d (2H, J1 7.0,
J2 5.0 Hz), 0.98 t (3H, J 7.0 Hz), 1.66 br.s (1H), 2.07
quintet (2H, J 7.0 Hz), 2.36 br.d (2H, J 7.0 Hz), 5.47 d.t
(1H, J1 11.0, J2 7.0 Hz), 5.61 d.t (1H, J1 11.0, J2 7.0 Hz).
1-(8-Heptadecenyl)cyclopropanol (VIII). Yield
–1
68%. IR spectrum, cm : 3595, 3071. 1H NMR spectrum
(200 MHz), d, ppm: 0.42 d.d (2H, J1 5.0, J2 6.5 Hz),
0.72 d.d (2H, J1 5.0, J2 6.5 Hz), 0.89 t (3H, J 6.5 Hz),
1.12–1.44 m (22H), 1.52 br.s (2H), 1.90–2.10 m (4H),
2.66 br.s (1H), 5.35 t (2H, J 5.0 Hz). Found, %: C 81.15;
H 12.54. C20H38O. Calculated, %: C 81.56; H 13.01.
1-(2,5-Dideutero-3-methylpentyl)cyclopropanol
(Va-D) was obtained by the similar procedure from ethyl
3-pentenoate. The reaction mixture was treated with DCl
1
in D2O. Yield 86%. H NMR spectrum (400 MHz), d,
6-Methyloctan-3-one (IX). To a solution of 0.71 g
(0.5 mmol) of 1-(3-methylpentyl)cyclopropanol (Va) in
10 ml of tetrachloromethane was added 0.02 g (0.1 mmol)
of p-toluenesulsonic acid. The reaction mixture was boiled
for 10 min cooled to room temperature, and passed
through a bed of aluminum oxide (5 g). The solvent was
evaporated, and the residue was subjected to column
chromatography on silica gel (eluent cyclohexane–ethyl
acetate). Yield 0.68 g (95%). 1H NMR spectrum is con-
ppm: 0.44 d.d (2H, J1 6.0, J2 4.5 Hz), 0.74 d.d (2H,
J1 6.0, J2 4.5 Hz), 0.82–0.92 m (5H), 1.09–1.23 m (1H),
1.24–1.42 m (2H), 1.46–1.63 m (3H), 1.80 br.s (1H).
1-(3-Ethylpentyl)cyclopropanol (Vb). Yield 85%.
–1
1
IR spectrum, cm : 3593, 3073. H NMR spectrum
(400 MHz), d, ppm: 0.43 d.d (2H, J1 6.3, J2 5.0 Hz),
0.73 d.d (2H, J1 6.3, J2 5.0 Hz), 0.84 t (6H, J 7.4 Hz),
1.16–1.26 m (1H), 1.27 quintet (2H, J 7.0 Hz), 1.29 quintet
(2H, J 7.0 Hz), 1.42–1.55 m (4H), 1.78 br.s (1H).
13C NMR spectrum (100 MHz), d, ppm: 10.83, 13.46,
25.38, 28.60, 35.37, 40.25, 56.07. Mass spectrum, m/z:
27, 29, 41, 43 (100%), 55, 57, 69, 72, 84, 85, 109, 156
[M]+. Found, %: C 76.38; H 12.54. C10H20O. Calculated,
%: C 76.86; H 12.90.
–1
sistent with that published in [13]. IR spectrum, cm :
1720. 13C NMR spectrum (100 MHz), d, ppm: 7.76, 11.16,
18.82, 29.14, 30.38, 34.01, 35.70, 40.08, 212.00. Mass
spectrum, m/z: 29, 43, 57 (100%), 72, 85, 95, 113, 142 [M]+
.
5,8-Dideutero-6-methyloctan-3-one (IX-D) was
obtained in the same way from 1-(2,5-dideutero-3-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 42 No. 5 2006

KULINKOVICH et al.
664
3. Kulinkovich, O.G., Epstein, O.L., Isakov, V.E., and
Khmel’nitskaya, E.A., Synlett., 2001, p. 49.
methylpentyl)cyclopropanol (Va-D). Yield 95%. IR
–1
spectrum, cm : 1720. 1H NMR spectrum (400 MHz), d,
4. Dzhemilev, U.M., Ibragimov,A.G., Usp. Khim., 2000, vol.
69, p. 134; Dzhemilev, U.M. and Ibragimov,A.G., Izv. Akad.
Nauk, Ser. Khim., 1998, p. 816; Dzhemilev, U.M.,
Vostrikova, O.S., and Tolstikov, G.A., Usp. Khim., 1990,
vol. 59, p. 1972.
5. Kulinkovich, O.G., Pure Appl. Chem., 2000, vol. 72, p. 1715.
6. Kulinkovich, O.G., Savchenko, A.I., Sviridov, S.V., and
Vasilevsky, D.A., Mendeleev Commun., 1993, p. 230;
Epstein, O.L., Savchenko, A.I., and Kulinkovich, O.G., Tet-
rahedron Lett., 1999, vol. 40, p. 5935.
ppm: 0.85 d (3H, J 6.3 Hz), 0.82–0.87 m (2H), 1.05 t
(3H, J 7.3 Hz), 1.08–1.19 m (1H), 1.25–1.39 m (2H),
1.55–1.62 m (1H), 2.35–2.42 m (2H), 2.42 q (2H,
J 7.3 Hz). 13C NMR spectrum (100 MHz), d, ppm: 7.74,
10.85 t (J 19.0 Hz), 18.78, 29.00, 29.98 t (J 19.0 Hz),
33.88, 35.68, 39.97, 211.88. Mass spectrum, m/z: 29, 44,
57 (100%), 72, 86, 97, 115, 144 [M]+
.
The study was carried out under the financial support
of the Foundation for Basic Research of the Belarus’
Republic ( grant no. X01-165).
7. Isakov, V.E. and Kulinkovich, O.G., Synlett., 2003, p. 967.
8. Ioffe, A.I., Svyatkin, V.A., and Nefedov, O.M., Stroenie
proizvodnykh tsiklopropana (Structure of Cyclopropane
Derivatives), Moscw: Nauka, 1986, p. 6.
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