Reaction of alicyclic reformatsky reagents with 2,5-bis(arylmethylidene) cyclopentanones

Article abstract of DOI:10.1134/S1070428012060036

Reformatsky reaction of methyl 1-bromocyclobutane-, 1-bromocyclopentane-, 1-bromocyclohexane-, and 1-bromocycloheptanecarboxylates with 2,5-bis(arylmethylidene)cyclopentanones gave the corresponding 4′-aryl-7′-arylmethylidene-4′,5′,6′, 7′-tetrahydro-2′H-s

Full text of DOI:10.1134/S1070428012060036

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 6, pp. 767–771. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © N.F. Kirillov, A.G. Gavrilov, P.A. Slepukhin, M.I. Vakhrin, A.N. Vasyanin, S.N. Shurov, 2012, published in Zhurnal Organicheskoi
Khimii, 2012, Vol. 48, No. 6, pp. 771–775.
Reaction of Alicyclic Reformatsky Reagents
with 2,5-Bis(arylmethylidene)cyclopentanones
N. F. Kirillova, A. G. Gavrilova, P. A. Slepukhinb, M. I. Vakhrina,
A. N. Vasyanina, and S. N. Shurova
a Perm State National Research University, ul. Bukireva 15, Perm, 614990 Russia
e-mail: kirillov@psu.ru
b Postovskii Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences,
ul. S. Kovalevskoi/Akademicheskaya 22/20, Yekaterinburg, 620041 Russia
Received July 16, 2011
Abstract—Reformatsky reaction of methyl 1-bromocyclobutane-, 1-bromocyclopentane-, 1-bromocyclo-
hexane-, and 1-bromocycloheptanecarboxylates with 2,5-bis(arylmethylidene)cyclopentanones gave the
corresponding 4′-aryl-7′-arylmethylidene-4′,5′,6′,7′-tetrahydro-2′H-spiro[cycloalkane-1,3′-cyclopenta[b]pyran]-
2′-ones.
DOI: 10.1134/S1070428012060036
We previously reported on reactions of alicyclic
Reformatsky reagents with α,β-unsaturated ketones,
which led to the formation of substituted spirodihydro-
pyranones [1–3]. We now report on the Reformatsky
reaction of 2,5-bis(arylmethylidene)cyclopentanones
Va–Vf with organozinc compounds derived from
methyl 1-bromocyclobutane-, 1-bromocyclopentane-,
1-bromocyclohexane-, and 1-bromocycloheptanecar-
boxylates I–IV. The reaction followed the 1,4-addition
pattern with formation of intermediate adducts VIa–
VId, VIIa–VIIe, VIIIa–VIIIe, IXa, and IXb which
underwent intramolecular ring closure via elimination
of bromozinc methoxide, yielding 4′-aryl-7′-arylmeth-
ylidene-4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclobutane-
1,3′-cyclopenta[b]pyran]-2′-ones Xa–Xd, 4′-aryl-7′-
arylmethylidene-4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclo-
pentane-1,3′-cyclopenta[b]pyran]-2′-ones XIa–XIe,
4′-aryl-7′-arylmethylidene-4′,5′,6′,7′-tetrahydro-2′H-
spiro[cyclohexane-1,3′-cyclopenta[b]pyran]-2′-ones
XIIa–XIIe, and 4′-aryl-7′-arylmethylidene-4′,5′,6′,7′-
tetrahydro-2′H-spiro[cycloheptane-1,3′-cyclopenta-
[b]pyran]-2′-ones XIIIa and XIIIb, respectively
(Scheme 1).
The product structure was confirmed by elemental
1
analysis and IR and H NMR spectroscopy. The IR
spectra of X–XIII characteristically contained absorp-
tion bands due to stretching vibrations of C=C bonds
(1650–1685 cm–1) and lactone carbonyl groups (1750–
1
1765 cm–1). In the H NMR spectra of these com-
pounds we observed only one set of signals, among
Scheme 1.
Ar
O
( )n
( )n
2
1
4'
Br
OZnBr
5'
7'
3'
2'
Zn
6'
COOMe
Ar
+
1'
O
Ar
Ar
–MeOZnBr
( )n
O
COOMe
Ar
Ar
Xa–Xd, XIa–XIe
I–IV
Va–Vf
VIa–VId, VIIa–VIIe
VIIIa–VIIIe, IXa, IXb
XIIa–XIIe, XIIIa, XIIIb
I, VI, X, n = 1; II, VII, XI, n = 2; III, VIII, XII, n = 3; IV, IX, XIII, n = 4; V, Ar = Ph (a), 4-BrC6H4 (b), 4-ClC6H4 (c),
2-FC6H4 (d), 3,4-(MeO)2C6H3 (e), 2,4-Cl2C6H3 (f); VI, X, Ar = Ph (a), 4-BrC6H4 (b), 2-FC6H4 (c), 2,4-Cl2C6H3 (d); VII, XI, Ar =
Ph (a), 4-BrC6H4 (b), 4-ClC6H4 (c), 2-FC6H4 (d), 3,4-(MeO)2C6H3 (e); VIII, XII, Ar = Ph (a), 4-BrC6H4 (b), 4-ClC6H4 (c),
3,4-(MeO)2C6H3 (d), 2,4-Cl2C6H3 (e); IX, XIII, Ar = Ph (a), 3,4-(MeO)2C6H3 (b).
767

KIRILLOV et al.
768
which the most typical was the 4′-H singlet in the
region δ 3.17–4.43 ppm.
hydropyran ring, the energies of two possible stereo-
isomers of Xa were calculated in terms of the SCF MO
LCAO approximation [B3LYP/6-31G(d)]. The calcu-
lated total energy of stereoisomer A with axial orienta-
tion of the phenyl substituent turned out to be slightly
lower than that of alternative isomer B. Therefore,
structure A seems to be more probable. Taking into
account that quantum-chemical calculations simulate
behavior of molecules in the gas phase, we performed
X-ray diffraction study on a single crystal of com-
pound Xa (see figure).
The configuration of the exocyclic double bond in
1
Xa was determined by detailed analysis of its H and
13C NMR spectra with the aid of 2D experiments
1
1
(1H–13C HMQC, H–1H ROESY, H–13C HMBC).
Signals from methylene carbon atoms were assigned
on the basis of the DEPT spectrum. In addition, the
13C NMR spectrum of Xa was compared to the spec-
trum of 7-benzylidene-3,3-dimethyl-4-phenyl-3,4,6,7-
tetrahydrocyclopenta[b]pyran-2(5H)-one (XIV) which
was synthesized by reaction of methyl 2-bromo-2-
methylpropanoate with zinc and 2,5-dibenzylidene-
cyclopentanone (Va) (Scheme 2).
(eq)
(eq)
(ax)
(ax)
H
Ph
Ph
H
Scheme 2.
O
O
O
O
O
Br
Ph
Ph
H
H
OMe
+
A
B
Me
Ph
Ph
Me
Etot = –1078.2186 au
Etot = –1078.2144 au
O
Va
Ph
According to the X-ray diffraction data, compound
Xa crystallized in centrosymmetric space group be-
longing to monoclinic crystal system. The bond
lengths in molecule Xa are typical of such structures.
In particular, the conjugated diene fragment is
characterized by shortened single C7–C24 bond
[1.4474(17) Å] and somewhat extended double C4–C24
[1.3253(16) Å] and C7–C8 bonds [1.3398(17) Å]. The
cyclopentene fragment is planar: the maximal devia-
tion from the mean-square plane is less than 0.015 Å.
The pyran ring has a pseudoenvelope conformation
with the O1, C24, C4, C3, and C1 atoms lying in one
plane within 0.05 Å; the C2 atom deviates from that
plane by 0.851 Å. The phenyl substituent on C3
occupies pseudoaxial position, so that the H3 proton is
pseudoequatorial. Thus molecules Xa in crystal have
structure A. Molecules Xa in crystal are packed in
layers extended along the [001] plane.
Me
Me
Zn
–MeOZnBr
O
O
Ph
XIV
gHMBC experiments for compounds Xa and XIV
revealed a coupling between the CH benzylidene pro-
ton and C7a and a weaker coupling of the same proton
with C6; these findings led us to assign E configuration
to the exocyclic double bond in Xa and XIV.
With a view to elucidate orientation (axial or
equatorial) of the aryl substituent on C4 in the tetra-
C21
O2
C1
C22
C23
O1
C2
C10
C24
C8
EXPERIMENTAL
C3
C9
C11
C12
C4
C5
C7
C6
C15
The IR spectra were recorded on a Specord 75IR
spectrometer from samples dispersed in mineral oil.
C20
C16
C17
1
13
C14
C19
C13
The H NMR spectra and the C NMR spectra of Xa,
Xd, XIa, and XIV were measured from solutions in
CDCl3 on a Varian Mercury Plus-300 spectrometer
C18
1
(300 MHz for H) using tetramethylsilane as internal
Structure of the molecule of 7′-benzylidene-4′-phenyl-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclobutane-1,3′-cyclopenta-
[b]pyran]-2′-one (Xa) according to the X-ray diffraction
data; non-hydrogen atoms are shown as thermal vibration
ellipsoids with a probability of 50%.
reference.
Quantum-chemical calculations of stereoisomers A
and B of Xa with complete geometry optimization
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REACTION OF ALICYCLIC REFORMATSKY REAGENTS
769
were performed using Firefly 8.0.0 software package
[4] (Linux, CentOS 5.5 6×AMD Athlon X2 4800).
one (Xa). Yield 0.87 g (51%), mp 124–125°C. IR
1
spectrum, ν, cm–1: 1760 (C=O), 1670 (C=C). H NMR
spectrum, δ, ppm: 1.80–2.60 m (8H, 5′-H, CH2), 2.85–
3.05 m (2H, 6′-H), 3.67 s (1H, 4′-H), 6.58 s (1H,
=CH), 7.07 d and 7.14–7.42 m (10H, Ph, J = 8.1 Hz).
13C NMR spectrum, δC, ppm: 14.88 (C3), 24.89 (C2),
27.50 (C6′), 28.81 (C5′), 34.69 (C4), 46.98 (C1), 51.16
(C4′), 117.44 (CH=), 122.53 (C4′a), 126.30 (Cp in
PhCH=), 127.47 [Cp in 4′-Ph), 127.55 (Co in 4′-Ph),
128.13 (Co in PhCH=), 128.36 (Cm in 4′-Ph), 128.84
(Cm in PhCH=), 136.63 (C7′), 137.35 (Ci in PhCH=),
137.76 (Ci in 4′-Ph), 149.01 (C7′a), 172.21 (C2′=O).
Found, %: C 84.40; H 6.26. C24H22O2. Calculated, %:
C 84.18; H 6.48.
The X-ray diffraction data for compound Xa were
acquired on an Xcalibur S automatic diffractometer
with a CCD detector [MoKα irradiation, 295(2) K,
graphite monochromator, ω-scanning through a step of
1°] according to a standard procedure from a colorless
0.45×0.37×0.21-mm single crystal. No correction for
absorption was introduced (μ = 0.077 mm–1). Mono-
clinic crystal system, space group P21/c; unit cell
parameters: a = 17.718(2), b = 6.2946(6), c =
17.814(2) Å; β = 112.719(12)°; V = 1832.6(4) Å3;
C24H22O2; Z = 4; dcalc = 1.241 g/cm3. Total of 8437
reflection intensities were measured in the range
2.75 < θ < 26.37°; 3600 reflections were independent
(Rint = 0.0256), and 1903 reflections had I > 2σ(I);
completeness 96.2% for θ < 26.37°. The structure was
solved by the direct method and was refined by F2 by
the full-matrix least-squares procedure in anisotropic
approximation for all non-hydrogen atoms using
SHELXTL-97 software package [5]. Hydrogen atoms
were localized by the spatial electron density peaks
and were involved in the refinement procedure in
isotropic approximation according to the riding model.
The final divergence factors were R1 = 0.0349, wR2 =
0.0618 [for reflections with I > 2σ(I)] and R1 = 0.0767,
wR2 = 0.0651 for all reflections. The maximal and
minimal electron density peaks were 0.129 and
–0.138 ē/Å3. The X-ray diffraction data for compound
Xa were deposited to the Cambridge Crystallographic
Data Centre (entry no. CCDC 875583) and are avail-
able at www.ccdc.cam.ac.uk/data_request/cif.
7′-(4-Bromobenzylidene)-4′-(4-bromophenyl)-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclobutane-1,3′-
cyclopenta[b]pyran]-2′-one (Xb). Yield 1.38 g (55%),
mp 175–176°C. IR spectrum, ν, cm–1: 1765 (C=O),
1
1685 (C=C). H NMR spectrum, δ, ppm: 1.75–2.61 m
(8H, 5′-H, CH2), 2.85–3.00 m (2H, 6′-H), 3.63 s (1H,
4′-H), 6.51 s (1H, =CH); 6.95 d, 7.24 d, 7.42 d, and
7.45 d (2H each, C6H4, J = 8.4 Hz). Found, %:
C 57.81; H 4.17; Br 32.26. C24H20Br2O2. Calculated,
%: C 57.63; H 4.03; Br 31.95.
7′-(2-Fluorobenzylidene)-4′-(2-fluorophenyl)-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclobutane-1,3′-
cyclopenta[b]pyran]-2′-one (Xc). Yield 0.85 g (45%),
mp 124–125°C. IR spectrum, ν, cm–1: 1765 (C=O),
1
1670 (C=C). H NMR spectrum, δ, ppm: 1.76–2.69 m
(8H, 5′-H, CH2), 2.78–3.00 m (2H, 6′-H), 4.16 s (1H,
4′-H), 6.76 s (1H, =CH), 6.93–7.49 m (8H, C6H4).
Found, %: C 75.96; H 5.42. C24H20F2O2. Calculated,
%: C 76.18; H 5.33.
4′-Aryl-7′-arylmethylidene-4′,5′,6′,7′-tetrahydro-
2′H-spiro[cycloalkane-1,3′-cyclopenta[b]pyran]-2′-
ones Xa–Xd, XIa–XIe, XIIa–XIIe, XIIIa, and XIIIb
(general procedure). A mixture of 1.5 g of fine zinc
turnings, a catalytic amount of mercury(II) chloride,
5 mmol of 2,5-bis(arylmethylidene)cyclopentanone
Va–Vf, 5.2 mmol of methyl 1-bromocycloalkanecar-
boxylate, 20 ml of benzene, 5 ml of ethyl acetate, and
1 ml of HMPA was heated for 4 h under reflux. The
mixture was cooled, and the solution was separated
from excess zinc by decanting and treated with 5% hy-
drochloric acid. The organic layer was separated, the
aqueous phase was extracted twice with ethyl acetate,
the extracts were combined with the organic phase and
dried over anhydrous sodium sulfate, the solvent was
distilled off, and the residue was recrystallized from
ethyl acetate.
7′-(2,4-Dichlorobenzylidene)-4′-(2,4-dichloro-
phenyl)-4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclo-
butane-1,3′-cyclopenta[b]pyran]-2′-one (Xd). Yield
1.20 g (50%), mp 143–144°C. IR spectrum, ν, cm–1:
1
1765 (C=O), 1675 (C=C). H NMR spectrum, δ, ppm:
1.68–2.69 m (8H, 5′-H, CH2), 2.76–2.91 m (2H, 6′-H),
4.43 s (1H, 4′-H), 6.81 s (1H, =CH); 6.88 d, 7.17 d,
7.19 d, 7.39 d, 4.40 s, and 7.42 s (6H, C6H3, J =
8.7 Hz). 13C NMR spectrum, δC, ppm: 15.12 (C3),
24.71 (C2), 27.16 (C6′), 28.77 (C5′), 34.94 (C4), 45.71
(C4′), 46.59 (C1), 113.28 (CH=), 122.93 (C4′a), 126.67
(C5 in ArCH=), 128.24 (C5 in 4′-Ar), 128.74 (C6 in
4′-Ar), 128.88 (C6 in ArCH=), 129.55 (C3 in ArCH=),
129.56 (C3 in 4′-Ar); 132.47, 133.69, 133.91, 134.43,
134.61, 134.76 (C1, C2, C4 in Ar), 138.90 (C7′), 149.74
(C7′a), 171.29 (C2′=O). Found, %: C 60.28; H 3.60;
Cl 29.31. C24H18Cl4O2. Calculated, %: C 60.03;
H 3.78; Cl 29.53.
7′-Benzylidene-4′-phenyl-4′,5′,6′,7′-tetrahydro-
2′H-spiro[cyclobutane-1,3′-cyclopenta[b]pyran]-2′-
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KIRILLOV et al.
770
7′-Benzylidene-4′-phenyl-4′,5′,6′,7′-tetrahydro-
cm–1: 1760 (C=O), 1675 (C=C). 1H NMR spectrum, δ,
ppm: 1.35–2.15 m (8H, CH2), 2.35–2.52 m (2H, 5′-H),
2.83–3.00 m (2H, 6′-H), 3.17 s (1H, 4′-H), 3,78 s and
3.84 s (12H, MeO), 6.46 s (1H, =CH); 6.54 s, 6.62 d,
6.75 d, 6.86 d, 6.93 s, and 6.99 d (6H, C6H3, J =
8.4 Hz). Found, %: C 72.81; H 6.89. C29H32O6. Calcu-
lated, %: C 73.09; H 6.77.
2′H-spiro[cyclopentane-1,3′-cyclopenta[b]pyran]-
2′-one (XIa). Yield 0.98 g (55%), mp 149–150°C. IR
1
spectrum, ν, cm–1: 1760 (C=O), 1660 (C=C). H NMR
spectrum, δ, ppm: 1.28–2.11 m (8H, CH2), 2.35–
2.53 m (2H, 5′-H), 2.84–3.04 m (2H, 6-H), 3.28 s (1H,
4′-H), 6.59 s (1H, =CH), 7.06 d and 7.15–7.41 m (10H,
Ph, J = 7.5 Hz). 13C NMR spectrum, δC, ppm: 24.83
(C3), 25.24 (C4), 27.54 (C6′), 28.72 (C5′), 32.79 (C2),
39.81 (C5), 51.97 (C4′), 53.40 (C1), 117.26 (CH=),
124.42 (C4′a), 126.26 (Cp in PhCH=), 127.37 (Cp in
4′-Ph), 127.76 (Co in 4-Ph), 128.12 (Co in PhCH=),
128.36 (Cm in 4′-Ph), 128.77 (Cm in PhCH=), 136.80
(C7′), 137.41 (Ci in PhCH=), 139.29 (Ci in 4′-Ph),
148.94 (C7′a), 173.44 (C2′=O). Found, %: C 84.59;
H 6.61. C25H24O2. Calculated, %: C 84.24; H 6.79.
7′-Benzylidene-4′-phenyl-4′,5′,6′,7′-tetrahydro-
2′H-spiro[cyclohexane-1,3′-cyclopenta[b]pyran]-
2′-one (XIIa). Yield 0.93 g (50%), mp 166–167°C. IR
1
spectrum, ν, cm–1: 1760 (C=O), 1650 (C=C). H NMR
spectrum, δ, ppm: 1.15–2.09 m (10H, CH2), 2.30–
2.52 m (2H, 5′-H), 2.82–3.05 m (2H, 6′-H), 3.45 s (1H,
4′-H), 6.57 s (1H, =CH), 7.06 d and 7.15–7.41 m (10H,
Ph, J = 7.2 Hz). Found, %: C 84.14; H 6.92. C26H26O2.
Calculated, %: C 84.29; H 7.07.
7′-(4-Bromobenzylidene)-4′-(4-bromophenyl)-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclopentane-1,3′-
cyclopenta[b]pyran]-2′-one (XIb). Yield 1.21 g
(47%), mp 176–177°C. IR spectrum, ν, cm–1: 1760
(C=O), 1670 (C=C). 1H NMR spectrum, δ, ppm: 1.24–
2.11 m (8H, CH2), 2.32–2.54 m (2H, 5′-H), 2.79–
3.01 m (2H, 6′-H), 3.26 s (1H, 4′-H), 6.52 s (1H,
=CH); 6.94 d, 7.24 d, 7.43 d, and 7.45 d (2H each,
C6H4, J = 8.4 Hz). Found, %: C 58.60; H 4.18;
Br 30.84. C25H22Br2O2. Calculated, %: C 58.39;
H 4.31; Br 31.08.
7′-(4-Bromobenzylidene)-4′-(4-bromophenyl)-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclohexane-1,3′-
cyclopenta[b]pyran]-2′-one (XIIb). Yield 1.53 g
(58%), mp 168–169°C. IR spectrum, ν, cm–1: 1760
(C=O), 1670 (C=C). 1H NMR spectrum, δ, ppm: 0.97–
2.12 m (10H, CH2), 2.28–2.49 m (2H, 5′-H), 2.73–
2.97 m (2H, 6′-H), 3.39 s (1H, 4′-H), 6.41 s (1H,
=CH); 6.85 d, 7.14 d, 7.39 d, and 7.41 d (2H each,
C6H4, J = 8.4 Hz). Found, %: C 59.35; H 4.43;
Br 30.01. C26H24Br2O2. Calculated, %: C 59.11;
H 4.58; Br 30.25.
7′-(4-Chlorobenzylidene)-4′-(4-chlorophenyl)-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclopentane-1,3′-
cyclopenta[b]pyran]-2′-one (XIc). Yield 1.02 g
(48%), mp 158–159°C. IR spectrum, ν, cm–1: 1765
(C=O), 1670 (C=C). 1H NMR spectrum, δ, ppm: 1.18–
2.19 m (8H, CH2), 2.30–2.51 m (2H, 5′-H), 2.79–
3.00 m (2H, 6′-H), 3.23 s (1H, 4′-H), 6.45 s (1H,
=CH), 6.90 d and 7.06–7.28 m (8H, C6H4, J = 8.4 Hz).
Found, %: C 70.78; H 5.11; Cl 16.46. C25H22Cl2O2.
Calculated, %: C 70.59; H 5.21, Cl 16.67.
7′-(4-Chlorobenzylidene)-4′-(4-chlorophenyl)-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclohexane-1,3′-
cyclopenta[b]pyran]-2′-one (XIIc). Yield 1.14 g
(52%), mp 166–167°C. IR spectrum, ν, cm–1: 1765
(C=O), 1670 (C=C). 1H NMR spectrum, δ, ppm: 1.07–
2.08 m (10H, CH2), 2.29–2.53 m (2H, 5′-H), 2.79–
3.05 m (2H, 6′-H), 3.44 s (1H, 4′-H), 6.51 s (1H,
=CH); 6.99 d, 7.25 d, and 7.28–7.31 m (8H, C6H4,
J = 8.4 Hz). Found, %: C 71.23; H 5.40; Cl 15.97.
C26H24Cl2O2. Calculated, %: C 71.07; H 5.51; Cl 16.14.
7′-(2-Fluorobenzylidene)-4′-(2-fluorophenyl)-
4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclopentane-1,3′-
cyclopenta[b]pyran]-2′-one (XId). Yield 0.84 g
(43%), mp 142–143°C. IR spectrum, ν, cm–1: 1760
(C=O), 1670 (C=C). 1H NMR spectrum, δ, ppm: 1.29–
2.18 m (8H, CH2), 2.32–2.56 m (2H, 5′-H), 2.78–
3.05 m (2H, 6′-H), 3.77 s (1H, 4′-H), 6.77 s (1H,
=CH), 6.99–7.49 m (8H, C6H4). Found, %: C 76.34;
H 5.78. C25H22F2O2. Calculated, %: C 76.51; H 5.65.
7′-(2,4-Dichlorobenzylidene)-4′-(2,4-dichloro-
phenyl)-4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclohex-
ane-1,3′-cyclopenta[b]pyran]-2′-one (XIId). Yield
1.50 g (59%), mp 185–186°C. IR spectrum, ν, cm–1:
1
1765 (C=O), 1660 (C=C). H NMR spectrum, δ, ppm:
1.22–2.15 m (10H, CH2), 2.26–2.56 m (2H, 5′-H),
2.72–2.96 m (2H, 6′-H), 4.23 s (1H, 4′-H), 6.79 s (1H,
=CH); 6.93 d, 7.18 d, 7.19 d, 7.39 d, 4.40 s, and 7.41 s
(6H, Cl2C6H3), J = 8.7 Hz). Found, %: C 61.69;
H 4.52; Cl 27.63. C26H22Cl4O2. Calculated, %:
C 61.44; H 4.36; Cl 27.90.
7′-(3,4-Dimethoxybenzylidene)-4′-(3,4-dime-
thoxyphenyl)-4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclo-
pentane-1,3′-cyclopenta[b]pyran]-2′-one (XIe).
Yield 1.69 g (71%), mp 171–172°C. IR spectrum, ν,
7′-(3,4-Dimethoxybenzylidene)-4′-(3,4-dime-
thoxyphenyl)-4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclo-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 6 2012

REACTION OF ALICYCLIC REFORMATSKY REAGENTS
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hexane-1,3′-cyclopenta[b]pyran]-2′-one (XIIe).
Yield 1.52 g (62%), mp 155–156°C. IR spectrum, ν,
cm–1: 1760 (C=O), 1665 (C=C). 1H NMR spectrum, δ,
ppm: 1.05–2.06 m (10H, CH2), 2.35–2.54 m (2H,
5′-H), 2.84–3.04 m (2H, 6′-H), 3.93 s (1H, 4′-H);
3.82 s, 3.83 s, 3.88 s, and 3.89 s (12H, MeO); 6.50 s
(1H, =CH); 6.55 s, 6.63 d, 6.76 d, 6.86 d, 6.94 s, and
6.98 d (6H, C6H3, J = 8.4 Hz). Found, %: C 73.58;
H 7.11. C30H34O6. Calculated, %: C 73.45; H 6.99.
synthesized from methyl 2-bromo-2-methylpropano-
ate, zinc, and 2,5-bis(benzylidene)cyclopentanone.
Yield 0.71 g (43%), mp 140–141°C. IR spectrum, ν,
cm–1: 1760 (C=O), 1665 (C=C). 1H NMR spectrum, δ,
ppm: 1.01 s (3H, Me), 1.44 s (3H, Me), 2.31–2.49 m
(2H, 5-H), 2.80–3.02 m (2H, 6-H), 3.25 s (1H, 4-H),
6.59 s (1H, =CH), 7.03 d and 7.11–7.42 m (10H, Ph,
J = 7.9 Hz). 13C NMR spectrum, δC, ppm: 22.69 (Me),
27.38 (C6), 27.49 (Me), 28.54 (C5), 42.07 (C3), 52.78
(C4), 117.34 (CH=), 123.45 (C4a), 126.21 (Cp in
PhCH=), 127.38 (Cp in 4-Ph), 127.98 (Co in 4-Ph),
128.05 (Co in PhCH=), 128.27 (Cm in 4-Ph), 128.62
(Cm in PhCH=), 136.63 (Ci in PhCH=), 137.34 (C7),
138.40 (Ci in 4-Ph), 148.53 (C7a), 173. 47 (C2=O).
Found, %: C 83.42; H 6.87. C23H22O2. Calculated, %:
C 83.60; H 6.71.
7′-Benzylidene-4′-phenyl-4′,5′,6′,7′-tetrahydro-
2′H-spiro[cycloheptane-1,3′-cyclopenta[b]pyran]-
2′-one (XIIIa). Yield 1.10 g (57%), mp 118–119°C. IR
1
spectrum, ν, cm–1: 1755 (C=O), 1660 (C=C). H NMR
spectrum, δ, ppm: 1.02–2.08 m (12H, CH2), 2.27–
2.48 m (2H, 5′-H), 2.79–3.01 m (2H, 6-H), 3.34 s (1H,
4′-H), 6.49 s (1H, =CH), 6.88–7.39 m (10H, Ph).
Found, %: C 84.59; H 7.48. C27H28O2. Calculated, %:
C 84.34; H 7.34.
This study was performed under financial support
by the Ministry of Education and Science of the
Russian Federation (project no. 3.3925.2011).
7′-(3,4-Dimethoxybenzylidene)-4′-(3,4-dime-
thoxyphenyl)-4′,5′,6′,7′-tetrahydro-2′H-spiro[cyclo-
heptane-1,3′-cyclopenta[b]pyran]-2′-one (XIIIb).
Yield 1.49 g (59%), mp 170–171°C. IR spectrum, ν,
cm–1: 1750 (C=O), 1660 (C=C). 1H NMR spectrum, δ,
ppm: 1.04–2.08 m (12H, CH2), 2.31–2.50 m (2H,
5′-H), 2.79–2.98 m (2H, 6′-H), 3.27 s (1H, 4′-H);
3.78 s, 3,79 s, 3.84 s, and 3.85 s (12H, MeO); 6.50 s
(1H, =CH); 6.56 s, 6.63 d, 6.72 d, 6.81 d, 6.86 s, and
6.95 d (6H, C6H3, J = 8.4 Hz). Found, %: C 73.64;
H 7.05. C31H36O6. Calculated, %: C 73.79; H 7.19.
REFERENCES
1. Kirillov, N.F. and Gavrilov, A.G., Russ. J. Gen. Chem.,
2008, vol. 78, p. 1422.
2. Kirillov, N.F. and Gavrilov, A.G., Russ. J. Org. Chem.,
2008, vol. 44, p. 963.
3. Kirillov, N.F., Gavrilov, A.G., Vasyanin, A.N., Shu-
rov, S.N., Vakhrin, M.I., and Slepukhin, P.A., Russ. J.
Gen. Chem., 2012, vol. 82, p. 289.
4. http://classic.chem.msu.su/gran/firefly/index.html
7-Benzylidene-3,3-dimethyl-4-phenyl-3,4,6,7-
5. Sheldrick, G.M., Acta Crystallogr., Sect. A, 2008, vol. 64,
tetrahydrocyclopenta[b]pyran-2(5H)-one (XIV) was
p. 112.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 6 2012