Reaction of perfluorinated 1-ethyl-, 1,1-diethyl-, and 1,2- diethylcyclobutabenzenes with pentafluorobenzene in SbF5

Article abstract of DOI:10.1134/S1070428007110152

Perfluoro(1-ethyl-1,2-dihydrocyclobutabenzene) reacts with pentafluorobenzene in SbF5 to give perfluoro(1-ethyl-2-phenyl-1,2- dihydrocyclobutabenzene). Analogous reaction of a mixture of perfluoro(1,1-diethyl-1,2-dihydrocyclobutabenzene) and perfluoro(1,2

Full text of DOI:10.1134/S1070428007110152

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2007, Vol. 43, No. 11, pp. 1677–1685. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © V.R. Sinyakov, T.V. Mezhenkova, V.M. Karpov, V.E. Platonov, 2007, published in Zhurnal Organicheskoi Khimii, 2007, Vol. 43,
No. 11, pp. 1678–1686.
Reaction of Perfluorinated 1-Ethyl-,
1,1-Diethyl-, and 1,2-Diethylcyclobutabenzenes with
Pentafluorobenzene in SbF5
V. R. Sinyakov, T. V. Mezhenkova, V. M. Karpov, and V. E. Platonov
Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Division, Russian Academy of Sciences,
pr. Akademika Lavrent’eva 9, Novosibirsk, 630090 Russia
e-mail: mtv@nioch.nsc.ru
Received March 12, 2007
Abstract—Perfluoro(1-ethyl-1,2-dihydrocyclobutabenzene) reacts with pentafluorobenzene in SbF5 to give
perfluoro(1-ethyl-2-phenyl-1,2-dihydrocyclobutabenzene). Analogous reaction of a mixture of perfluoro-
(1,1-diethyl-1,2-dihydrocyclobutabenzene) and perfluoro(1,2-diethyl-1,2-dihydrocyclobutabenzene) leads to the
formation (after hydrolysis of the reaction mixture) of perfluorinated 7-phenyl-8,8-diethylbicyclo[4.2.0]octa-
1,4,6-trien-3-one, 1,1-diethyl-2-(4-oxocyclohexa-2,5-dienylidene)-1,2-dihydrocyclobutabenzene, and 2-(pent-
2-en-3-yl)benzophenone (from the 1,1-isomer) and perfluorinated (E)-1,2-diethyl-1-phenyl-1,2-dihydrocyclo-
butabenzene, 7,8-diethyl-8-phenylbicyclo[4.2.0]octa-1,4,6-trien-3-one, and 1-[2-(1-phenylprop-1-en-1-yl)-
phenyl]propan-1-one (from the 1,2-isomer).
DOI: 10.1134/S1070428007110152
We previously studied reactions of perfluorinated
cyclobutabenzene, indan, tetrahydronaphthalene [1],
1-methylcyclobutabenzene [2], 1-ethyl- and 1,1-di-
ethylindans, and 1-ethyltetrahydronaphthalene [3] with
pentafluorobenzene in the presence of SbF5, which led
to the formation of the corresponding pentafluoro-
phenylcycloalkabenzenes. The reactions with per-
fluorinated 1-phenylindan, 1-phenyltetrahydronaph-
thalene, and 1-arylcyclobutabenzenes with antimony
pentafluoride were found to involve skeletal rearrange-
ments [4].
SbF5 with a view to obtain polyfluorinated cyclobuta-
benzenes containing both pentafluorophenyl and pen-
tafluoroethyl groups. These compounds are necessary
for studying the general relations holding in skeletal
transformations of polyfluoroarylcycloalkabenzenes.
Compound I reacted with C6F5H in SbF5 to produce
(after treatment of the reaction mixture first with an-
hydrous hydrogen fluoride and then with water) per-
fluoro(1-ethyl-2-phenyl-1,2-dihydrocyclobutabenzene
(IV, E/Z isomer ratio 70:30), perfluoro(2-ethyl-1-
phenyl-1,2-dihydrocyclobutabenzen-1-ol) (V) (E/Z iso-
mer ratio ~42:58), and a small amount of perfluoro(1-
ethyl-1-phenyl-1,2-dihydrocyclobutabenzene) (VI)
(Scheme 1). Compound VI was also obtained by reac-
tion of perfluoro(1-phenyl-1,2-dihydrocyclobutaben-
zene) (VII) (prepared from perfluorocyclobutabenzene
VIII and C6F5H in SbF5 [1]) with tetrafluoroethylene
In continuation of our studies on pentafluorophen-
ylation of polyfluorocycloalkabenzenes in the present
work we examined reactions of perfluorinated 1-ethyl-
1,2-dihydrocyclobutabenzene (I), 1,1-diethyl-1,2-dihy-
drocyclobutabenzene (II), and 1,2-diethyl-1,2-dihydro-
cyclobutabenzene (III) with pentafluorobenzene in
Scheme 1.
(1) C6F5H, SbF5, 25°C
(2) HF
(3) H2O
C2F5
6
3
6
C2F5
C2F5
C2F5
OH
1
2
1
C6F5
5
4
4
5
5
4
+
+
F
F
F
F
F
F
F
F
1
2
2
2'
1'
3
6
3
C6F5
3'
4'
6'
5'
I
IV
V
VI
1677

SINYAKOV et al.
1678
Scheme 2.
C2F5
C6F5
3
(1) CF2=CF2, SbF5
(2) H2O
C6F5
2
C6F5H, SbF5
4
5
VI
+
F
F
F
F
F
1
O
6
VIII
VII
IX
CF2CF2
C6F5
C6F5
F–
SbF5
CF2=CF2
VII
VI
F
F
F
F
X
Scheme 3.
C2F5
C6F5
SbF5, SO2ClF
H2O
IV
V
F
F
XI
C2F5
C6F5
SbF5, SO2ClF
H2O
VI
IX
+
VI
F
F
XII
in the presence of SbF5. In this case, no 1,2-isomer IV
was formed, but the reaction mixture contained per-
fluoro(2-ethyl-2-phenyl-1,2-dihydrocyclobutabenzen-
1-one) (IX) (Scheme 2).
The formation of hydroxy derivative V and ketone
IX under the above conditions may be rationalized as
follows. Compounds IV and VI in SbF5 are likely to
exist as cations XI and XII, respectively. In fact, cat-
ions XI and XII were detected by 19F NMR spectros-
copy upon dissolution of compounds IV and VI in the
system SbF5–SO2ClF. Hydrolysis of a solution con-
taining cation XI yields mainly compound V, whereas
a mixture of precursor of VI and ketone IX is obtained
from cation XII (Scheme 3).
Presumably, ethylcyclobutabenzene I reacts with
C6F5H in SbF5 according to the scheme proposed
previously for the reactions of cyclobutabenzene VIII
and perfluoro(1-methyl-1,2-dihydrocyclobutabenzene)
with C6F5H [1,2]. Product VI is formed from com-
pound VII via alkylation of tetrafluoroethylene with
perfluoro(1-phenyl-1,2-dihydrocyclobutabenzen-1-yl)
cation (X) generated from cyclobutabenzene VII by
the action of SbF5 [1] (Scheme 2) in a way similar
to the reaction of polyfluorocyclobutabenzenes with
fluorinated olefins in the presence of SbF5 [5, 6].
Fluorinated alcohol V is stable in acid medium but
is converted into a mixture of perfluoro[2-(prop-1-en-
1-yl)benzophenone] (XIII) and 2-(1,2,2,3,3,3-hexa-
fluoropropyl)nonafluorobenzophenone (XIV) on treat-
ment with an aqueous solution of potassium carbonate
Scheme 4.
F
3
3
1''
C2F5
OH
2'' CF3
F
CFHCF2CF3
COC6F5
4
4
5
K2CO3, 20–25°C
+
F
F
F
F
5
COC6F5
6
6
C6F5
V
XIII
XIV
XIII
XIV
C2F5
CFCF2CF3
–F–
OH–
V
F
F
F
O
C6F5
H2O
COC6F5
A
B
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007

REACTION OF PERFLUORINATED 1-ETHYL-, 1,1-DIETHYL-, ...
1679
or during chromatography on a column charged with
silica gel (pH ≥ 7). Presumably, deprotonation of
hydroxy derivative V gives anion A which undergoes
opening of the four-membered ring (like haloform
reaction) with formation of anion B. Protonation of the
latter yields compound XIV, while elimination of
fluoride ion leads to product XIII (Scheme 4).
converted mainly into compound XV, while the
amount of ketones XVI and XVII is insignificant.
1,1-Isomer II yields perfluorinated 8,8-diethyl-7-phen-
ylbicyclo[4.2.0]octa-1,4,6-trien-3-one (XIX), 4-(2,2-
diethyl-1,2-dihydrocyclobutabenzen-1-ylidene)cyclo-
hexa-2,5-dien-1-one (XX), and 2-(pent-2-en-3-yl)ben-
zophenone (XXI, E/Z ratio 40:60). In addition, the re-
action mixture contained a small amount of perfluoro-
4-[5-(cis-1,2-diethyl-2-phenyl-1,2-dihydrocyclobuta-
benzen-1-yloxy)-2,2-diethyl-1,2-dihydrocyclobuta-
benzen-1-ylidene]cyclohexa-2,5-dien-1-one (XXII)
(Scheme 5). During isolation of compounds XVII and
XXI by column chromatography or on prolonged
storage the E isomer was converted (either partially or
completely) into the Z isomer.
In the reaction of a mixture of isomeric diethyl-
cyclobutabenzenes II and III with 0.5 equiv of C6F5H
in 10 equiv of SbF5, only 1,2-isomer III is involved.
After treatment of the reaction mixture with water,
a mixture of perfluorinated (E)-1,2-diethyl-1-phenyl-
1,2-dihydrocyclobutabenzene (XV), 7,8-diethyl-8-
phenylbicyclo[4.2.0]octa-1,4,6-trien-3-one (XVI), and
1-[2-(1-phenylprop-1-en-1-yl)phenyl]propan-1-one
(XVII, E/Z ratio ~83:17) was obtained. 1,1-Isomer II
gives rise to perfluoro(2,2-diethyl-1,2-dihydrocyclo-
butabenzen-1-one) (XVIII) (Scheme 5). In the pres-
ence of an equimolar amount of pentafluorobenzene
(5 equiv of antimony pentafluoride), both isomers II
and III are involved. In this case, 1,2-isomer III is
A probable mechanism of the above transforma-
tions is shown in Scheme 6. 1,1-Diethylcyclobutaben-
zene II in SbF5 loses fluoride ion to form perfluoro-
(2,2-diethyl-1,2-dihydrocyclobutabenzen-1-yl) cation
(XXIII). Alkylation of pentafluorobenzene with cation
XXIII gives compound V which is converted into per-
Scheme 5.
(1) C6F5H (0.5 mol)
SbF5 (10 mol), ~25°C
(2) H2O
C2F5
C2F5
C2F5
C6F5
C2F5
C6F5
2
F
5
C2F5
C2F5
O
3
1
8
F
F
+
F
F
F
F
+
4
7
6
C2F5
C2F5
III, 0.55 mol
II, 0.45 mol
XV
XVI
C6F5
C2F5
3
1''
F
2''
C2F5
4
5
+
F
+
F
3''CF3
COCF2CF3
O
6
XVII
XVIII
(1) C6F5H (1 mol)
SbF5 (5 mol), ~25°C
(2) H2O
C2F5
C2F5
C2F5
2
6
O
3
1
6
C2F5
5
8
1
II + III (55:45)
XV
+
+
F
F
4
4
6'
7
2
C6F5
5
3
5'
F
2'
3'
O
XIX
XX
C2F5
C2F5
3''
CF3
C2F5
3
F
6
6'
6
1''
O
2''
C2F5
4
5
5'
4'
1'
2'
5
1
+
+
F
F
4
F
6''
2
o'
COC6F5
3
3'
C2F5
5''
m'
F
2''
F
o
p'
3''
m
O
XXI
XXII
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007

SINYAKOV et al.
1680
Scheme 6.
C2F5
C2F5
C2F5
C2F5
C2F5
C2F5
SbF5
C6F5H
–H+
SbF5
H2O
II
XIX + XX
F
F
F
F
F
C6F5
C6F5
C2F5
XXIII
C
XXIV
C2F5
C2F5
C2F5
C2F5
H2O
C2F5
COC6F5
XXIV
XXI
F
F
F
–H+
–F–
OH
C6F5
O
C6F5
D
E
F
fluoro(2,2-diethyl-1-phenyl-1,2-dihydrocyclobutaben-
zen-1-yl) cation (XXIV). Hydrolysis of the latter leads
to ketones XIX and XX and probably to alcohol D.
Opening of the four-membered ring in structure D (like
haloform reaction) yields benzophenone XXI through
intermediate anions E and F (Scheme 6).
through intermediate hydroxy derivative H in a way
similar to the formation of benzophenone XXI shown
in Scheme 6. Compound XXII may result from the re-
action of alcohol H with cation XXIV or/and of cation
XXV with ketone XIX through intermediate ion J
(Scheme 7). This transformation is likely to occur in
the course of treatment of the reaction mixture with
water, i.e., when the mixture contains simultaneously
hydrolysis products and cyclobutabenzene salts.
Perfluoro(1,2-diethyl-1,2-dihydrocyclobutabenzene)
(III) in SbF5 is likely to converted into cation G which
alkylates pentafluorobenzene to give compound XV.
Elimination of fluoride ion from XV by the action of
SbF5 yields cyclobutenyl cation XXV, and hydrolysis
of the latter yields compounds XVI and XVII
(Scheme 7). Presumably, compound XVII is formed
The formation of cations XXIV and XXV in the
reaction of cyclobutabenzenes II and III with C6F5H in
SbF5 was detected by 19F NMR spectroscopy. In ad-
dition, we found that cation XXIII is generated from
Scheme 7.
C2F5
C6H5
C2F5
C2F5
SbF5
SbF5
C6F5H
–H+
H2O
III
XV
XVI + XVII
F
F
C2F5
F
G
XXV
XVII
C2F5
C2F5
C2F5
O
C6F5
C2F5
H2O
XXIV
F
J
F
F
–H+
–F–
OH
C6F5
C6F5
C2F5
C2F5
H
XXV
C2F5
C2F5
C2F5
O
XIX
H2O
F
F
XXII
C6F5
C6F5
C2F5
J
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007

REACTION OF PERFLUORINATED 1-ETHYL-, 1,1-DIETHYL-, ...
1681
1,1-diethylcyclobutabenzene II in antimony penta-
fluoride and that the concentration of the correspond-
ing cation G derived from 1,2-isomer III is insufficient
to be detected by 19F NMR spectroscopy. Nevertheless,
as we already noted, 1,2-isomer III reacts with C6F5H
at a higher rate than does 1,1-isomer II. Presumably,
the reaction of pentafluorobenzene with cation XXIII
is hindered for steric reasons (Scheme 6): the cationic
center in XXIII is sterically shielded by two bulky
pentafluoroethyl groups. By contrast, cation G allows
pentafluorobenzene molecule to approach the cationic
center at the side opposite to the C2F5 group on the
neighboring carbon atom (Scheme 7).
J2″,3″ and J3″,2′(6′) of 9 and 4 Hz, respectively, which are
typical of cis arrangement of the CF3 and C6F5 groups.
In the spectrum of Z-XVII the CF3 signal appears as
a doublet (J2″,3″' = 9 Hz). The Z isomer of XXI is
characterized by a doublet signal from the CF3 group
at the double C=C bond (J2″,3″' = 8 Hz); the corre-
sponding signal of the E isomer of XXI has a more
complex structure indicating cis orientation of the CF3
and C2F5 groups with respect to the double bond.
EXPERIMENTAL
The 19F NMR spectra of the reaction mixtures,
SbF5–SO2ClF solutions containing perfluorinated cati-
onic species, and solutions of individual compounds in
The patterns observed in the NMR spectra of
cations XI, XII, XXIII–XXV are consistent with
published data for perfluoro(cyclobutabenzen-1-yl)
cation [6] and cation X [1].
1
CHCl3, as well as the H NMR spectrum of ketone
XIV, were recorded on a Bruker AC-200 instrument at
188.3 MHz for 19F and 200 MHz for 1H. The 19F NMR
spectra of E-XV and XIX were recorded on a Bruker
AM-400 instrument (376.4 MHz), and of Z-XV and
XXII, on a Bruker AV-300 spectrometer (282.4 MHz).
The chemical shifts were measured using C6F6 and
SO2ClF (δF 262.8 ppm relative to C6F6) or residual
solvent signal (CHCl3, δ 7.24 ppm) as internal refer-
ences. The elemental compositions were determined
from the high-resolution mass spectra which were
obtained on a Finnigan MAT-8200 mass spectrometer.
GLC analysis was performed on an LKhM-72 chroma-
tograph [4000×4-mm column; stationary phase VS-1
or E-301 on Chromosorb W, 15(25):100; carrier gas
helium, flow rate 60 ml/min]. GC–MS analysis was
performed on a Hewlett–Packard G1081A GC–MS
system consisting of an HP 5890 Series II gas chro-
matograph (HP5 capillary column, 30 m×0.25 mm×
0.25 μm, 5% of diphenyl- and 95% of dimethylsilox-
ane; carrier gas helium, 1 ml/min) and an HP 5971
mass-selective detector (electron impact, 70 eV).
The structure of compounds IV–VI, IX, and XIII–
XXII was determined on the basis of their 19F NMR
and high-resolution mass spectra. In addition, the
molecular and crystalline structures of XVI, XX, and
XXII were studied by X-ray diffraction [7]. The coor-
dinates of atoms and geometric parameters of their
molecules were deposited to the Cambridge Crystallo-
graphic Data Center (entry nos. 635 817–635819).
Signals in the 19F NMR spectra were assigned taking
into account their position, multiplicity, and intensity.
The 19F NMR data were also used to determine the
configuration of molecules IV, V, XIII, XV, XVII,
and XXI.
In the spectra of the E isomers of IV and V, signals
from fluorine atoms at tertiary carbon atoms appear in
a weaker field relative to the corresponding signals of
the Z isomers, as in the spectra of polyfluorinated
methylphenylcyclobutabenzenes [2]. Fluorine atoms in
the CF2 groups of the perfluoroethyl substituents in
E-XV (cis arrangement of the C2F5 groups) appear as
Reaction of perfluoro(1-ethyl-1,2-dihydrocyclo-
butabenzene) (I) with pentafluorobenzene in SbF5.
A mixture of 4.02 g (11.6 mmol) of compound I,
7.52 g (34.7 mmol) of SbF5, 2.14 g (12.7 mmol) of
C6F5H, and 6 ml of C6F6 was stirred for 4 h at 25–27°C
in a Teflon vessel. The mixture was then treated with
16 ml of anhydrous hydrogen fluoride, poured into an
ice–water mixture, and extracted with chloroform. The
organic phase was separated, washed with water, and
dried over MgSO4, and the solvent and C6F6 were
distilled off to obtain 5.2 g of a mixture containing*
38% of (E)-perfluoro(1-ethyl-2-phenyl-1,2-dihydro-
doublets with coupling constants JAA′ = 52 and JBB′
=
56 Hz, while the corresponding coupling constants for
trans-oriented perfluoroethyl groups in isomer Z-XV
do not exceed 5 Hz. Signals from fluorine nuclei in the
vinyl group of E-XIII are split into doublets with
a coupling constant J1″,2′' of 141 Hz, indicating their
trans orientation; signals from the cis-fluorine atoms in
Z-XIII are characterized by a coupling constant of
7 Hz. The chemical shifts of the vinylic fluorine atoms
and the corresponding coupling constants are consist-
ent with the data reported for perfluoro(1-phenylprop-
1-enes) [8].
In the 19F NMR spectrum of E-XVII, the CF3C=
signal is a doublet of triplets with coupling constants
* Hereinafter, the compositions of product mixtures are given in
wt % according to the GLC and 19F NMR data.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007

SINYAKOV et al.
1682
cyclobutabenzene) (E-IV, yield 33%), 16% of (Z)-per-
fluoro(1-ethyl-2-phenyl-1,2-dihydrocyclobutabenzene
(Z-IV, yield 14%), 18% of (Z)-perfluoro(2-ethyl-1-
phenyl-1,2-dihydrocyclobutabenzen-1-ol) (Z-V, yield
16%), 13% of (E)-perfluoro(2-ethyl-1-phenyl-1,2-di-
hydrocyclobutabenzen-1-ol) (E-V, yield 11%), and 6%
of perfluoro(1-ethyl-1-phenyl-1,2-dihydrocyclobuta-
benzene (VI, yield 5.5%). A 2.57-g portion of the
product mixture was subjected to column chromatog-
raphy on silica gel using as eluent chloroform which
was preliminarily shaken with concentrated hydro-
chloric acid (10:1, by volume) and separated. We thus
isolated 1.1 g of compound IV (E/Z ratio 71:29) and
two fractions containing compound V (0.34 g with E/Z
ratio ~14:86 and 0.14 g with E/Z ratio ~92:8).
Perfluoro(1-ethyl-1-phenyl-1,2-dihydrocyclo-
butabenzene) (VI). A mixture of 1.87 g (7.54 mmol)
of perfluorinated cyclobutabenzene VIII, 4.9 g
(22.6 mmol) of SbF5, 1.39 g (8.27 mmol) of C6F5H,
and 6 ml of C6F6 was stirred for 3.5 h at 25°C, 1.5 g
(15 mmol) of tetrafluoroethylene was passed through
the mixture over a period of 2.5 h at 27–29°C, and the
mixture was treated with water at 10–20°C, acidified
with 5% hydrochloric acid, and extracted with chloro-
form. The organic phase was separated and dried over
MgSO4, and the solvent and hexafluorobenzene were
distilled off to leave 3.5 g of a mixture containing
compound VI and perfluoro(2-ethyl-2-phenyl-1,2-di-
hydrocyclobutabenzen-1-one) (IX) at a ratio of 86:14
(19F NMR data) and a small amount (<5%) of per-
fluoro(1,2-diethyl-1-phenyl-1,2-dihydrocyclobutaben-
zene) (XV, E/Z ratio ~2:1). The product mixture was
subjected to column chromatography on silica gel
using first hexane and then chloroform (preliminarily
treated as described above) to isolate 2.9 g of a mixture
containing 88% of compound VI (yield 68%), 5% of
E-XV, 2% of Z-XV, and 0.4 g of IX (yield 11%). By
several experiments we obtained 9.57 g of a mixture
containing 74% of VI, 9% of E-XV, and 5% of Z-XV.
It was subjected to column chromatography on silica
gel using hexane as eluent to isolate 0.25 g of pure
Z-XV, 5.2 g of VI, and 4 g of fractions containing
compounds VI and XV at different ratios.
By repeated chromatography of 1.1 g of compound
IV (E/Z ratio 71:29) on silica gel (eluent hexane) we
isolated a fraction (0.45 g) enriched in the E isomer
(E/Z ratio ~83:17) and a fraction (0.07 g) enriched in
the Z-isomer (E/Z ratio ~45:55). 19F NMR spectrum,
δF, ppm: isomer E-IV: 80.9 (3F, CF3), 45.2 (1F, FA)
and 36.7 (1F, FB) (CF2CF3), 32.4 (1F, 2-F), 29.2 (1F,
6-F), 28.2 (1F, 3-F), 20.4 (1F, 4-F), 19.7 (1F, 5-F), 11.3
(1F, 1-F), 22.8 (2F, 2′-F, 6′-F), 14.8 (1F, 4′-F), 2.2
(2F, 3′-F, 5′-F); JFF, Hz: JAB = 293, J3, 4 = 18, J3, 5 = 8,
J
3,6 = 23, J4,5 = 18, J4,6 = 9, J5,6 = 18, J3,2′(6′) = 12,
J(6-F,CF3) = 18; isomer Z-IV: 80.3 (3F, CF3), 41.3 (1F,
FA) and 33.6 (1F, FB) (CF2CF3), 31.1 (1F, 2-F), 29.7
(1F, 6-F), 27.5 (1F, 3-F), 20.2 (1F, 4-F), 19.8 (1F, 5-F),
5.5 (1F, 1-F), ~18 i ~29 (2F, 2′-F, 6′-F), 14.4 (1F, 4′-F),
Compound VI. 19F NMR spectrum, δF, ppm: 81.0
(3F, CF3), 49.4 (1F, FA) and 43.5 (1F, FB) (CF2CF3),
72.9 (1F, 2-FA) and 63.8 (1F, 2-FB), 34.9 (1F, 6-F), 25.5
(1F, 3-F), 20.3 (1F, 5-F), 17.6 (1F, 4-F), 20.6 (1F, 2′-F),
30.5 (1F, 6′-F), 13.7 (1F, 4′-F), 2.2 and 2.0 (1F each,
3′-F, 5′-F); JFF, Hz: JAB = 280, J2A,2B = 203, J3,4 = 20,
~2 (2F, 3′-F, 5′-F); JFF, Hz: JAB = 290, J3,4 ≈ 19, J3,5
≈
9, J3,6 ≈ 24, J3,2′(6′) ≈ 9. Found: [M]+ 495.9743 (for E/Z
mixture, ~45:55). C16F16. Calculated: M 495.9744. The
mass spectra (GC–MS) of Z-IV and E-IV contained
the molecular ion peaks with m/z 496.
J3,5 = 8, J3,6 = 23, J4,5 = 18, J4,6 = 10, J5,6 = 18, J6,2′
=
95, J(6-F,CF3) = 20, J6′,A = 8, J6′,B = 61, J6′,2A = 33,
JA,2B = JB,2B = 21. Found: [M]+ 495.9743. C16F16. Cal-
culated: M 495.9744.
Compound V. 19F NMR spectrum, δF, ppm: isomer
E-V: 80.7 (3F, CF3), 46.7 (1F, FA) and 35.6 (1F, FB)
(CF2CF3), 28.4 (1F, 3-F), 26.0 (1F, 6-F), 19.0 (1F, 5-F),
16.7 (1F, 4-F), 20.9 (2F, 2′-F, 6′-F), 11.5 (1F, 1-F), 12.2
Compound IX. mp 67–71°C (from hexane).
19F NMR spectrum, δF, ppm: 80.9 (3F, CF3), 47.8 (2F,
CF2CF3), 35.2 (1F, 3-F), 34.6 (1F, 6-F), 28.2 (1F, 4-F),
17.8 (1F, 5-F), 26.2 (2F, 2′-F, 6′-F), 13.2 (1F, 4′-F), 2.4
(2F, 3′-F, 5′-F); JFF, Hz: J3, 4 = 8, J3,5 = 9, J3, 6 = 23,
J4,5 = 18, J4,6 = 11, J5,6 = 20, J3,2′(6′) ≈ 40, J(3-F,CF3) =
9. Found: [M]+ 473.9729. C16F14O. Calculated:
M 473.9725.
Compound Z-XV. 19F NMR spectrum, δF, ppm:
81.5 (3F, 1-CF2CF3), 80.7 (3F, 2-CF2CF3), 56.9 (1F,
1-CFA) and 45.8 (1F, 1-CFB), 42.1 (1F, 2-CFA) and 34.1
(1F, 2-CFB), 33.0 (1F, 6-F), 27.6 (1F, 3-F), 19.8 (1F,
(1F, 4′-F), 1.7 (2F, 3′-F, 5′-F); JFF, Hz: JAB = 291, J3,4
18, J3,5 = 8, J3,6 = 24, J(3-F,CF3) = 19, J4,5 = 19, J4,6
=
=
7, J5,6 = 19, J6,2′(6′) = 12; isomer Z-V: 80.6 (3F, CF3),
41.8 (1F, FA) and 33.8 (1F, FB) (CF2CF3), 29.2 (1F,
3-F), 25.7 (1F, 6-F), 19.3 (1F, 5-F), 16.3 (1F, 4-F), 18.2
and 26.2 (2F, 2′-F, 6′-F), 4.5 (1F, 1-F), 12.0 (1F, 4′-F),
1.3 (2F, 3′-F, 5′-F); JFF, Hz: JAB = 290, J3,4 = 18, J3,5
9, J3,6 ≈ 24, J(3-F,CF3) = 21, J4,5 = 19, J4,6 = 7, J5,6
=
=
19, J6,2′(6′) ≈ 9. Found: [M]+ 493.9779 (E/Z ratio ~14:
86), 493.9799 (E/Z ratio ~92:8). C16HF15O. Calculat-
ed: M 493.9788.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007

REACTION OF PERFLUORINATED 1-ETHYL-, 1,1-DIETHYL-, ...
1683
5-F), 17.4 (1F, 4-F), 18.7 (1F, 2′-F), 35.4 (1F, 6′-F), 7.5
(1F, 2-F), 14.6 (1F, 4′-F), 2.1 (2F, 3′-F, 5′-F); JFF, Hz:
J1A,1B = 271, J2A,2B = 280, J3,4 = 19, J3,5 = 9, J3,6 = 22,
a ratio of 62:38 (19F NMR data). The product mixture
was dissolved in 2 ml of chloroform, 2 g of 10%
aqueous K2CO3 was added, and the mixture was stirred
for 4 h at 22°C and treated as described above to
isolate 0.19 g of a mixture of XIII and XIV at the
same ratio. A 1.13-g portion of that mixture was sub-
jected to column chromatography on silica gel using
hexane as eluent to isolate 0.15 g of a mixture of
E-XIII and Z-XIII (82:18), 0.48 g of E-XIII, and
0.36 g of XIV.
J(3-F, 2-CF3) = 21, J4,5 = 19, J4,6 = 10, J5,6 = 19, J6,2′
=
67, J(6-F,1-CF3) = 28, J6′,1B = 130, J6′,2B = 62. Found:
[M]+ 595.9684. C18F20. Calculated: M 595.9680.
Perfluoro(2-ethyl-1-phenyl-1,2-dihydrocyclo-
butabenzen-1-yl) cation (XI). Compound IV, 0.23 g
(0.46 mmol), was dissolved in 0.99 g (4.57 mmol) of
SbF5, and 0.3 g of SO2ClF was added. The resulting
solution contained cation XI and no precursor IV (19F
NMR data). It was poured into an ice–water mixture
and extracted with chloroform, the extract was dried
over MgSO4, and the solvent was distilled off to leave
0.17 g of a mixture of compounds V (E/Z ratio 45:55)
and IV (E/Z ratio 70:30) at a ratio of ~93:7 (19F NMR
data). 19F NMR spectrum of cation XI, δF, ppm: 82.8
(3F, CF3), 51.4 (1F, FA) and 42.9 (1F, FB) (CF2CF3),
77.3 (1F, 4-F), 69.1 (1F, 6-F), 35.5 (2F, 3-F, 5-F), 30.3
(1F, 2-F), 59.0 (1F, 2′-F), 61.1 (1F, 6′-F), 71.5 (1F,
Compound E-XIII. mp 71–72.5°C (from hexane).
19F NMR spectrum, δF, ppm: 93.7 (3F, CF3), 30.9 (1F,
3-F), 24.7 (1F, 6-F), 17.2 (1F, 4-F), 16.0 (1F, 5-F), 21.7
(2F, 2′-F, 6′-F), 17.5 (1F, 4′-F), 2.8 (2F, 3′-F, 5′-F), 29.6
(1F, 1″-F), 0.8 (1F, 2″-F). JFF, Hz: J3,4 = 21, J3,5 = 8,
J3,6 = 12, J3,2″ = 18, J4,5 = 19, J4,6 = 8, J5,6 = 22, J1″,2″
=
141, J(1″-F, CF3) = 21, J(2″-F, CF3) = 11. Found:
[M]+ 473.9734. C16F14O. Calculated: M 473.9725.
Compound Z-XIII. 19F NMR spectrum (from E/Z
isomer mixture, ~82:18), δF, ppm: 92.9 (3F, CF3), 29.8
(1F, 3-F), 25.4 (1F, 6-F), 17.7 (1F, 4-F), 16.5 (1F, 5-F),
21.5 (2F, 2′-F, 6′-F), 17.2 (1F, 4′-F), 2.8 (2F, 3′-F, 5′-F),
50.8 (1F, 1″-F), 15.5 (1F, 2″-F); JFF, Hz: J3, 4 = 22,
4′-F), 12.9 (2F, 3′-F, 5′-F); JFF, Hz: JA,B = 285, J3,4
J4,5 = 18, J4,6 = 40, J2,6′ ≈ 65, JB,6′ = 69, J6,2′ = 170.
=
Perfluoro(2-ethyl-2-phenyl-1,2-dihydrocyclo-
butabenzen-1-yl) cation (XII). Compound VI, 0.24 g
(0.48 mmol), was dissolved in 1.09 g (5.03 mmol) of
SbF5, and 0.19 g of SO2ClF was added. The resulting
solution contained cation XII and no precursor VI (19F
NMR data). It was poured into an ice–water mixture
and extracted with chloroform, the extract was dried
over MgSO4, and the solvent was distilled off to leave
0.22 g of a mixture of compounds VI and IX at a ratio
of 1:1 (19F NMR data). 19F NMR spectrum of cation
XII, δF, ppm: 83.1 (3F, CF3), 52.3 (2F, CF2CF3), 214.6
(1F, 1-F), 107.2 (1F, 4-F), 78.8 (1F, 6-F), 47.8 (1F,
3-F), 36.8 (1F, 5-F), 26.2 (2F, 2′-F, 6′-F), 20.8 (1F,
J
3,5 = 8, J3,6 = 11, J4,5 = 19, J4,6 = 8, J5,6 = 22, J1″,2″ = 7,
J(1″-F,CF3) = 6, J(2″-F,CF3) = 13. GC–MS data for
E/Z mixture: m/z 474 [M]+.
Ketone XIV. mp 57.5–58.5°C (from hexane).
1H NMR spectrum: δ 6.35 ppm, d.d. 19F NMR spec-
trum, δF, ppm: 79.1 (3F, CF3), –38.4 (1F, CFH), 40.6
(1F, FA) and 32.5 (1F, FB) (CF2CF3), 28.8 (1F, 3-F),
23.7 (1F, 6-F), 14.9 (1F, 4-F), 13.8 (1F, 5-F), 21.9 (2F,
2′-F, 6′-F), 17.7 (1F, 4′-F), 2.5 (2F, 3′-F, 5′-F); JFF, Hz:
J
A,B = 285, J3,4 = 20, J3,5 = 7, J3,6 = 11, J4,5 = 21, J4,6 =
2
3
7, J5, 6 = 23, JHF = 43, J(H, FB) = 20. Found:
[M]+ 493.9792. C16HF15O. Calculated: M 493.9788.
4′-F), 2.3 (2F, 3′-F, 5′-F); JFF, Hz: J1,4 = 40, J3,4 = J4,5
20, J4,6 = 55.
=
Reaction of perfluorinated 1,1-diethyl- and
1,2-diethyl-1,2-dihydrocyclobutabenzenes II and III
with pentafluorobenzene in SbF5. a. A mixture of
compounds II and III (45:55), 1.02 g (2.28 mmol),
was dissolved in 4.93 g (22.74 mmol) of SbF5.
According to the 19F NMR data, the solution contained
perfluoro(2,2-diethyl-1,2-dihydrocyclobutabenzen-1-yl)
cation (XXIII) and compound III. Pentafluoroben-
zene, 0.2 g (1.19 mmol), was added to the solution,
and the mixture was kept for 23 h at 23°C; it contained
cation XXIII and perfluoro(1,2-diethyl-2-phenylcyclo-
butabenzen-1-yl) cation (XXV) at a ratio of ~1:1,
while no other products were present (19F NMR data).
The mixture was treated with water at 0–5°C, acidified
with 5% hydrochloric acid, and extracted with chloro-
Reaction of perfluoro(2-ethyl-1-phenyl-1,2-dihy-
drocyclobutabenzen-1-ol) (V) with aqueous potas-
sium carbonate. Compound V, 0.21 g (0.43 mmol,
E/Z ratio 40:60), was dissolved in 2.5 ml of chloro-
form, 2.5 g of a 10% aqueous solution of potassium
carbonate (0.25 g, 1.81 mmol) was added, and the
mixture was stirred for 2 h at 25°C, treated with water,
acidified with 5% hydrochloric acid, and extracted
with chloroform. The extract was dried over MgSO4,
and the solvent was distilled off. The residue was 0.2 g
of a mixture of perfluoro[2-(prop-1-en-1-yl)benzo-
phenone] (XIII, E/Z ratio ~90:10) and 2-(1,2,2,3,3,3-
hexafluoropropyl)nonafluorobenzophenone (XIV) at
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007

SINYAKOV et al.
1684
form. The extract was dried over MgSO4, and the
solvent was distilled off. The residue was 1.06 g of
a mixture containing 8% of initial compound II, 7% of
XV (yield 10%, calculated on the initial compound
III), 26% of perfluoro(7,8-diethyl-8-phenylbicyclo-
[4.2.0]octa-1,4,6-trien-3-one) (XVI, yield 38%), 20%
of (E)-perfluoro{1-[2-(1-phenylprop-1-en-1-yl)phenyl]-
propan-1-one} (E-XVII, yield 29%), 4% of (Z)-per-
fluoro{1-[2-(1-phenylprop-1-en-1-yl)phenyl]propan-1-
one} (Z-XVII, yield 6%), and 28% of perfluoro(2,2-
diethyl-1,2-dihydrocyclobutabenzen-1-one) (XVIII).
A 0.93-g portion of the product mixture was subjected
to column chromatography on silica gel using as eluent
first carbon tetrachloride and then chloroform prelimi-
narily treated with concentrated hydrochloric acid as
described above. We thus isolated 0.19 g of compound
XVII (E/Z ratio ~80:20) and 0.16 g of XVI. By re-
peated chromatographic separation of 0.19 g of isomer
mixture XVII on silica gel (eluent hexane) we isolated
0.02 g of E-XVII and 0.03 g of Z-XVII.
Cation XXIII. 19F NMR spectrum, δF, ppm: 83.7
(6F, CF3), 57.0 (4F, CF2CF3), 210.5 (1F, 1-F), 114.3
(1F, 4-F), 84.7 (1F, 6-F), 44.3 (1F, 3-F), 40.5 (1F, 5-F);
JFF, Hz: J1,4 = 44, J3,4 = J4,5 = 20, J4,6 = 62.
b. A mixture of compounds II and III (45:55),
1.13 g (2.52 mmol), was dissolved in 2.74 g
(12.64 mmol) of SbF5, 0.47 g (2.8 mmol) of penta-
fluorobenzene was added, the mixture was stirred for
11 h at 27°C and was then kept for 14 h at that tem-
perature, and its 19F NMR spectrum was recorded. It
contained cations XXIII and XXV and perfluoro(2,2-
diethyl-1-phenylcyclobutabenzen-1-yl) cation (XXIV)
at a ratio of ~10:55:35, while no other products were
present. Hexafluorobenzene, 1 ml, was added, and the
mixture was treated as described above in a. We ob-
tained 1.36 g of a mixture containing 5% of compound
II, 44% of E-XV (yield 70%),** 3% of ketone XVI
(yield 5%), <3% of XVII, 2% of XVIII, 12% of per-
fluoro(8,8-diethyl-7-phenylbicyclo[4.2.0]octa-1,4,6-
trien-3-one) (XIX, yield 24%), 7% of perfluoro[4-(2,2-
diethyl-1,2-dihydrocyclobutabenzen-1-ylidene)cyclo-
hexa-2,5-dien-1-one] (XX, yield 14%), 5% of (E)-per-
fluoro[2-(pent-2-en-3-yl)benzophenone] (E-XXI, yield
10%), 7% of (Z)-perfluoro[2-(pent-2-en-3-yl)benzo-
phenone] (Z-XXI, yield 14%), and 6% of perfluoro-
{4-[5-(cis-1,2-diethyl-2-phenyl-1,2-dihydrocyclobuta-
benzen-1-yloxy)-2,2-diethyl-1,2-dihydrocyclobuta-
benzen-1-ylidene]cyclohexa-2,5-dien-1-one} (XXII,
yield 6%). A 1.23-g portion of that mixture was sub-
jected to column chromatography on silica gel using
carbon tetrachloride as eluent to isolate 0.42 g of
E-XV, 0.11 g of XXI (E/Z ratio 40:60), 0.9 g of XIX,
0.03 g of XXII, and 0.05 g of XX. By repeated chro-
matographic separation of 0.11 g of isomer mixture
E-XXI/Z-XXI on silica gel (eluent hexane) we isolated
0.025 g of pure Z-XXI.
Compound XVI. mp 89.5–91°C (from hexane).
19F NMR spectrum, δF, ppm: 81.7 (3F, CF3), 79.4 (3F,
CF3), 61.0 (1F, FA) and 45.6 (1F, FB, 8-CF2CF3), 48.8
(2F, 7-CF2CF3), 43.4 (1F, 2-F), 32.0 (1F, 4-F), 28.2
(1F, 5-F), 27.2 (2F, 2′-F, 6′-F), 15.0 (1F, 4′-F), 2.9 (2F,
3′-F, 5′-F); JFF, Hz: JA,B = 288, J2,4 = 7, J2,2′(6′) = 42,
J4,5 = 7. Found: [M]+ 573.9665. C18F18O. Calculated:
M 573.9662.
Isomer E-XVII. 19F NMR spectrum, δF, ppm: 91.2
(3F, 3″-F), 80.9 (3F, CF2CF3), 56.3 (1F, 2″-F), 41.7
(2F, CF2CF3), 29.9 (1F, 3-F), 29.6 (1F, 6-F), 18.0 (1F,
4-F), 13.5 (1F, 5-F), 24.0 and 25.0 (1F each, 2′-F, 6′-F),
13.5 (1F, 4′-F), 1.8 (2F, 3′-F, 5′-F); JFF, Hz: J3,4 = 20,
J3,5 = 7, J3,6 = 10, J3,2′(6′) ≈ 10, J4,5 = 21, J4,6 = 8, J5,6
=
21, J(6-F, CF3) = 7, J2″, 3″ = 9, J3″, 2′(6′) = 4. Found:
[M]+ 573.9662. C18F18O. Calculated: M 573.9662.
Cation XXIV. 19F NMR spectrum, δF, ppm (from
a mixture with XXIII and XXV): 83.8 (6F, CF3), 53.4
(4F, CF2CF3), 82.8 (1F, 4-F), 78.3 (1F, 6-F), 38.7 (1F,
3-F), 32.5 (1F, 5-F), 59–61 (2F, 2′-F, 6′-F), 71.9 (1F,
4′-F), 13.0–14.5 (2F, 3′-F, 5′-F).
Compound E-XV. 19F NMR spectrum, δF, ppm:
81.1 (3F, 1-CF2CF3), 81.0 (3F, 2-CF2CF3), 53.5 (1F,
F1A) and 47.6 (1F, F1B, 1-CF2CF3), 46.6 (1F, F2A) and
41.1 (1F, F2B, 2-CF2CF3), 33.3 (1F, 6-F), 27.9 (1F,
3-F), 20.0 (1F, 5-F), 17.3 (1F, 4-F), 19.9 (1F, 2′-F),
30.2 (1F, 6′-F), 22.7 (1F, 2-F), 14.4 (1F, 4′-F), 2.1 and
Isomer Z-XVII. 19F NMR spectrum, δF, ppm: 92.7
(3F, 3″-F), 80.7 (3F, CF2CF3), 57.6 (1F, 2″-F), 42.2
(1F, FA) and 40.8 (1F, FB) (CF2CF3), 30.7 (1F, 3-F),
28.9 (1F, 6-F), 17.6 (1F, 4-F), 13.7 (1F, 5-F), 24.9 (2F,
2′-F, 6′-F), 13.2 (1F, 4′-F), 1.9 (2F, 3′-F, 5′-F); JFF, Hz:
JA,B = 302, J3,4 = 21, J3,5 = 7, J3,6 = 10, J3,2′(6′) = 10,
J4, 5 = 20, J4, 6 = 8, J5, 6 = 21, J6, A = 22, J6, B = 28,
J(6-F, CF3) = 7, J2″, 3″ = 9, J2″, 2′(6′) = 17. Found:
[M]+ 573.9656. C18F18O. Calculated: M 573.9662.
Compound XVIII. 19F NMR spectrum, δF, ppm:
80.8 (6F, CF3), 50.6 (4F, CF2), 37.0 (1F, 6-F), 29.6 (1F,
4-F), 29.3 (1F, 3-F), 19.8 (1F, 5-F); JFF, Hz: J3,4 = 19,
J3,5 = 8, J3,6 = 23, J4,5 = 17, J4,6 = 13, J5,6 = 20. Found:
[M]+ 425.9729. C12F14O. Calculated: M 425.9725.
2.0 (1F each, 3′-F, 5′-F); JFF, Hz: J1A,1B = 274, J2A,2B
=
** The yields of XV–XVII were calculated on the initial isomer
III, and the yields of XIX–XXII, on isomer II.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007

REACTION OF PERFLUORINATED 1-ETHYL-, 1,1-DIETHYL-, ...
1685
288, J2,6′ = 22, J(2-F, CF3) = 17, J3, 4 = 19, J3,5 = 9,
J3,6 = 22, J(3-F,CF3) = 24, J4,5 = 19, J4,6 = 9, J5,6 = 18,
JA,B = 272, J2″,3 = 180, J6,2B ≈ J6,3B = 89, J1A,1B = 65,
JB,1A ≈ 50, J3′,o ≈ 55. Found: [M]+ 1147.9433. C36F36O2.
Calculated: M 1147.9323.
J
6,2′ = 69, J(6-F,CF3) = 27, J6′,1B = 59, J6′,1B = 57, J1A,2A =
52, J1B, 2B = 56, J1A, 2B = 13. Found: [M]+ 595.9673.
C18F20. Calculated: M 595.9680.
Perfluoro(1,2-diethyl-2-phenyl-1,2-dihydrocyclo-
butabenzen-1-yl) cation (XXV). Compound XV,
0.17 g (0.28 mmol), was dissolved in 0.88 g
(4.06 mmol) of SbF5, and 0.21 g of SO2ClF was added.
According to the 19F NMR data, the resulting solution
contained cation XXV and no precursor XV. The
solution was poured into an ice–water mixture and
extracted with chloroform, the extract was dried over
MgSO4, and the solvent was distilled off. The residue,
0.14 g, was a mixture of 57% of E-XV, 23% of XVI,
and 8% of ketone XVII. 19F NMR spectrum of cation
XXV, δF, ppm: 85.1 and 83.9 (3F each, CF3), 59.9 (1F,
FA) and 51.0 (1F, FB) (CF2CF3, JA,B = 290 Hz), 57.7
(1F, FA) and 52.3 (1F, FB) (CF2CF3, JA,B = 285 Hz),
140.7 (1F, 4-F), 91.5 (1F, 6-F), 52.8 (1F, 3-F), 39.4
(1F, 5-F), 27.2 (2F, 2′-F, 6′-F), 21.5 (1F, 4′-F), 7.3 (2F,
3′-F, 5′-F); JFF, Hz: J3,4 = J4,5 = 22, J4,6 = 80.
Compound XIX. 19F NMR spectrum, δF, ppm: 81.6
(6F, CF3), 51.0 (2F, FA) and 48.9 (2F, FB) (CF2CF3),
33.8 (1F, 2-F), 30.4 (1F, 4-F), 27.9 (1F, 5-F), 28.3 (2F,
2′-F, 6′-F), 19.8 (1F, 4′-F), 3.4 (2F, 3′-F, 5′-F); JFF, Hz:
J
A,B = 290, J2,4 = 8, J2,5 = 8, J4,5 = 8, J5,2′(6′) = 31. Found:
[M]+ 573.9655. C18F18O. Calculated: M 573.9662.
Compound XX. mp 88–89°C (after sublimation at
a residual pressure of 2 mm, 30°C). 19F NMR spectrum,
δF, ppm: 81.6 (6F, CF3), 53.8 (2F, FA) and 48.0 (2F, FB,
CF2CF3), 39.6 (1F, 3-F), 27.9 (1F, 6-F), 26.1 (1F, 5-F),
19.9 (1F, 4-F), 27.3 (1F, 6′-F), 25.4 (1F, 2′-F), 14.1
and 13.3 (1F each, 3′-F, 5′-F); JFF, Hz: JA, B = 290,
J3,4 = 18, J3,5 = 13, J3,6 = 22, J4,5 = 18, J4,6 = 8, J5,6
=
19, J6, B = 90, J3, 2′ = 178. Found: [M]+ 573.9655.
C18F18O. Calculated: M 573.9662.
Isomer E-XXI. 19F NMR spectrum (E/Z isomer
mixture, ~40:60), δF, ppm: 95.7 (3F, 3″-F), 78.7 (3F,
CF3), 67.9 (1F, 2″-F), 53.3 (1F, FA) and 52.0 (1F, FB)
(CF2CF3), 28.9 (1F, 3-F), 25.8 (1F, 6-F), 17.6 (1F,
4-F), 13.8 (1F, 5-F), 21.4 (2F, 2′-F, 6′-F), 16.8 (1F,
4′-F), 2.6 (2F, 3′-F, 5′-F); JFF, Hz: JA,B = 285, J3,4 = 21,
This study was performed under financial support
by the Russian Foundation for Basic Research (project
no. 06-03-32170).
REFERENCES
1. Karpov, V.M., Mezhenkova, T.V., Platonov, V.E., Sinya-
kov, V.R., and Shchegoleva, L.N., Russ. J. Org. Chem.,
2002, vol. 38, p. 1158.
2. Sinyakov, V.R., Mezhenkova, T.V., Karpov, V.M., Plato-
nov, V.E., Rybalova, T.V., and Gatilov, Yu.V., Russ. J.
Org. Chem., 2003, vol. 39, p. 837.
3. Sinyakov, V.R., Mezhenkova, T.V., Karpov, V.M., Plato-
nov, V.E., Rybalova, T.V., and Gatilov, Yu.V., Russ. J.
Org. Chem., 2006, vol. 42, p. 77.
4. Karpov, V.M., Mezhenkova, T.V., Platonov, V.E., and
Sinyakov, V.R., J. Fluorine Chem., 2001, vol. 107, p. 53;
Sinyakov, V.R., Mezhenkova, T.V., Karpov, V.M., and
Platonov, V.E., J. Fluorine Chem., 2004, vol. 125, p. 49;
Karpov, V.M., Mezhenkova, T.V., Platonov, V.E., and
Sinyakov, V.R., J. Fluorine Chem., 2002, vol. 117, p. 73.
J3,5 = 7, J3,6 = 10, J4,5 = 20, J4,6 = 9, J5,6 = 22, JB,3″
=
24, JA, 3″ = 10, J2″, 3″ ≈ 8, J(3″-F, CF3) ≈ 7. Found:
[M]+ 573.9666 (E/Z, ~40:60). C18F18O. Calculated:
M 573.9662.
Isomer Z-XXI. 19F NMR spectrum, δF, ppm: 92.5
(3F, 3″-F), 77.9 (3F, CF3), 58.7 (1F, 2″-F), 50.3 (1F,
FA) and 49.5 (1F, FB) (CF2CF3), 29.6 (1F, 3-F), 26.2
(1F, 6-F), 18.2 (1F, 4-F), 14.4 (1F, 5-F), 21.4 (2F, 2′-F,
6′-F), 16.7 (1F, 4′-F), 2.6 (2F, 3′-F, 5′-F); JFF, Hz:
JA, B = 278, J3, 4 = 22, J3, 5 = 7, J3, 6 = 11, J4, 5 = 20,
J4, 6 = 9, J5, 6 = 23, JA, 2″ = 29, JB, 2″ = 10, J2″, 3″ = 8,
J(2″-F, CF3) = 15.
Compound XXII. mp 160–166°C (from hexane–
CH2Cl2). 19F NMR spectrum, δF, ppm: 86.0 (3F,
1′-CF2CF3), 81.3 (9F, 1-CF2CF3, 2′-CF2CF3), 57.8 (1F,
FA) and 47.5 (1F, FB) (2′-CF2CF3), 56.1 (1F, FA) and
50.4 (1F, FB) (1′-CF2CF3), 55.1 (1F, FA) and 47.3 (1F,
FB) (1-CF2CF3), 52.3 (1F, FA) and 49.0 (1F, FB)
(1-CF2CF3), 39.8 (1F, 3-F), 37.7 (1F, o′-F), 33.0 (1F,
3′-F), 31.7 (1F, 4-F), 31.0 (1F, 6′-F), 28.0 (1F, 6-F),
26.5 (1F, 6″-F), 25.4 (1F, 2″-F), 19.9 (1F, o-F), 21.3
and 16.8 (1F each, 4′-F, 5′-F), 15.2 and 14.2 (1F each,
3″-F, 5″-F), 14.6 (1F, p-F), 2.2 and 1.6 (1F each, m-F,
m′-F); JFF, Hz: J1A,1B = 297, J3A,3B = 284, J2A,2B = 282,
5. Karpov, V.M., Mezhenkova, T.V., Platonov, V.E., and
Yakobson, G.G., J. Fluorine Chem., 1985, vol. 28, p. 121.
6. Karpov, V.M., Mezhenkova, T.V., Platonov, V.E., and
Yakobson, G.G., Izv. Akad. Nauk SSSR, Ser. Khim., 1985,
p. 2315.
7. Rybalova, T.V., Gatilov, Yu.V., Sinyakov, V.R., Mezhen-
kova, T.V., and Karpov, V.M., Zh. Strukt. Khim., 2008,
vol. 49, p. 123.
8. Belen’kii, G.G., Savicheva, G.I., Lur’e, E.P., and Ger-
man, L.S., Izv. Akad. Nauk SSSR, Ser. Khim., 1978,
p. 1640.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 11 2007