1328
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 7, July, 2001
Sadykov et al.
Scheme 3
Compound 2. 13C NMR (CDCl3), δ (the literature data2 are
given in parentheses): 43.3 (43.3) (C(1), C(2), C(10)); 33.1
(33.1) (C(3), C(9)); 35.7 (35.7) (C(4), C(8)); 34.0 (34.0) (C(5),
C(7)); 42.9 (42.9) (C(6)); 22.9 (22.8) ((C(3)CH3, C(9)CH3).
M = 166.
3040 °C
The reaction of cyclooctane with Bui3AlCCl4PdCl2.
Palladium dichloride (10.8 mg), cyclooctane (5 mL), and
Bui2AlH (1 mL) were placed in a three-neck round-bottom
flask equipped with a magnetic stirrer and a reflux condenser.
Then, a mixture of CCl4 (2 mL) and cyclooctane (2 mL) was
added dropwise at 810 °C. The reaction mixture was slowly
heated to 50 °C with continuous stirring. The evolution of HCl
started at ∼40 °C and lasted for 2 h. After the reaction was
completed, the reaction mixture separated into two layers. The
upper layer was withdrawn and passed through Al2O3.
Ethylcyclohexane and dimethylcyclohexane isomers were iso-
lated by preparative GLC. Ethylcyclohexane, 13C NMR
(CDCl3), δ: 39.7 (C(1)); 33.2 (C(2), C(6)); 26.6 (C(3), C(5));
26.9 (C(4)). The mixture of dimethylcyclohexane isomers con-
tained cis-1,3-dimethylcyclohexane (63%), trans-1,4-dimethyl-
cyclohexane (22%), trans-1,2-dimethylcyclohexane (11%), and
trans-1,3-dimethylcyclohexane (2%).
cis-1,3-Dimethylcyclohexane. 13C NMR, δ (the literature
data7 are given in parentheses): 33.1 (32.85) (C(1), C(3)); 44.8
(44.70) (C(2)); 35.4 (35.40) (C(4), C(6)); 26.7 (26.45) (C(5));
22.7 (22.85) (C(1)CH3, C(3)CH3).
trans-1,4-Dimethylcyclohexane. 13C NMR, δ (the litera-
ture data7 are given in parentheses): 32.8 (32.70) (C(1), C(4));
35.7 (35.65) (C(2), C(3), C(5), C(6)); 22.9 (22.70) (C(1)CH3,
C(4)CH3).
>99.5%
8090 °C
+
∼20%
∼80%
of polyhalogenomethane with aluminum chloride,6 which
is formed in the reaction of OAC with polyhalogeno-
methane in the presence of transition metal complexes
as catalysts.9 However, considering that the degree of
conversion of cyclohexane and the yields of the reaction
products are significantly higher than those observed
with other electrophilic catalytic systems, one cannot
exclude the process involves reduced forms of transition
metals.
Experimental
trans-1,2-Dimethylcyclohexane. 13C NMR, δ (the litera-
ture data7 are given in parentheses): 39.6 (39.55) (C(1), C(2));
36.1 (36.05) (C(3), C(6)); 27.1 (26.85) (C(4), C(5)); 20.6
(20.25) (C(1)CH3, C(2)CH3).
Reagent grade CCl4, CHCl3, and cyclohexane were used
without additional purification. Et3Al (91%), Bui3Al (91%),
Bui2AlH (73%), Et2AlCl (90%), and EtAlCl2 (86%) were com-
mercial chemicals. Cyclooctane and endo-tricyclo[5.2.1.02,6]de-
cane were prepared by hydrogenation of cyclooctadiene and the
cyclopentadiene dimer, respectively, over a nickel catalyst.10
13C NMR spectra were recorded on a JEOL-FX90Q spectro-
meter. The reaction mixtures were analyzed by GLC on a
Chrom-5 chromatograph with a capillary column (25 m;
5% SE-30) and on a Finnigan-4021 GLC/MS instrument.
Identification of compounds was performed with the use of a
database stored in the instrument´s computer. The reaction
products were separated on a Carlo Erba preparative chromato-
graph.
Transformations of cyclohexane. Carbon tetrachloride (8 mL,
83 mmol) was added dropwise in an atmosphere of argon at
≤10 °C to a mixture of cyclohexane (26 mL, 241 mmol),
Pd(acac)2 (78.5 mg, 0.256 mmol), and 5 mL of 91% Et3Al
(30 mmol). Addition of CCl4 was accompanied by the evolu-
tion of ethane and ethylene. The reaction mixture was stirred at
1012 °C for 3 h until HCl ceased to evolve. When the
reaction was completed, two layers were formed. The upper
layer was withdrawn and passed through Al2O3. GLC analysis
of the reaction products (20.3 g) showed that the content of
dimethyldecalins is 30% and that of the non-consumed cyclo-
hexane is 24%. Fractional distillation with a distilling column
at 200220 °C gave a liquid (4.5 g) containing isomer 1 (49%),
isomer 2 (38%), four unidentified dimethyldecalin isomers with
M = 166 (each 23%), and five isomers with M = 166
(each 0.20.3 %).
trans-1,3-Dimethylcyclohexane. 13C NMR, δ (the litera-
ture data7 are given in parentheses): 27.1 (27.05) (C(1), C(3));
41.5 (41.45) (C(2)); 34.0 (33.90) (C(4)); 20.9 (20.75) (C(5));
32.9 (32.90) (C(6)); 20.6 (20.50) (C(1)CH3, C(3)CH3).
The reaction of endo-tricyclo[5.2.1.02,6]decane with
Bui3AlCCl4PdCl2. To a stirred mixture of pentane (6 mL),
endo-tricyclo[5.2.1.02,6]decane (1.324 g), PdCl2 (10.8 mg), and
diisobutylaluminum hydride (1 mL), a mixture of CCl4 (2 mL)
and pentane (2 mL) was added dropwise at 1012 °C in an
atmosphere of Ar. After 40 min, the reaction mixture sepa-
rated into two layers. The upper layer was withdrawn and
passed through Al2O3. The resulting transparent liquid con-
tained exo-tricyclo[5.2.1.02,6]decane (99.5%). The content
was determined by GLC using the method of an internal
standard.
The exo-isomer, 13C NMR (CDCl3), δ: 48.4 (C(1), C(7));
40.9 (C(2), C(6)); 29.0 (C(3), C(5)); 27.5 (C(4)); 32.7 (C(8),
C(9)); 32.1 (C(10)). The starting endo-isomer, 13C NMR,
δ: 45.8 (C(1), C(7)); 41.9 (C(2), C(6)); 27.2 (C(3), C(5)); 29.0
(C(4)); 23.3 (C(8), C(9)); 43.5 (C(10)).
References
1. A. E. Shilov and G. B. Shul´pin, Aktivatsiya i kataliticheskie
reaktsii uglevodorodov [Activation and Catalytic Reactions
of Hydrocarbons], Nauka, Moscow, 1995, 398 pp. (in
Russian).
2. J. K. Whitesell and M. A. Minton, Stereochemical Analysis
of Alicyclic Compounds by C13 NMR Spectroscopy, Chapman
and Hall, LondonNew York, 1987, p. 231.
Compound 1. 13C NMR (CDCl3), δ (the literature data2 are
given in parentheses): 43.0 (43.0) (C(1), C(2), C(6), C(7));
33.1 (33.1) (C(3), C(8)); 35.6 (35.6) (C(4), C(9)); 34.3 (34.2)
(C(5), C(10)); 22.8 (22.8) (C(3)CH3, C(8)CH3). M = 166.