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Dodecahedranes from []Pagodanes

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same conditions, the conversion of 1 was ca. 60%), 12 was
formed nearly quantitatively from both 10 and 11.
The cleavage of one of the two a bonds in 1 could be
achieved, however, by hydrogenolysis. Heating of a 4%
mixture of 1 on Pd/C (10%) in an autoclave under H2 (10
atm H2, 300"C, 14 h) resulted in nearly quantitative formation (95% isolated yield) of the high-melting
(m.p. = 3 3 0 5 5"C), C,,-symmetric C2"H2, decacycle 13a
(decacyclo[' '.02 's.03~7.05~'2.0"~'".0'
' ".O l3.I7.O l 6 '"leicosane), the formal trapping product of the diradical 4 [ "]
(Scheme 4). Characteristic of the skeletal changes connected with the opening 1- 13a is, among other things,
the increase in the vicinal H,H coupling constants in the
'H-NMR spectrum (with decreasing torsional angle; 1 , HC3-C7-H=41.8"; 13a, H-C2-C3-H =27.8", H-C3-C7H=20.9"; 2, H-C-C-H=O"). The low-field position of the
2(12) H signal (6=2.39, CDCI,) reflects the trend, which
culminates in 6=3.38 for the perfect eclipsed orientation
of the vicinal C-H bonds in 2. The X-ray structure analysis of 13a, also carried out as a control of the MM2 data,
failed (as also was the case for the dibromide 13d; cf.,
however, 13e"'I) on account of crystallographic disorder.
A structure simulating that of the diene 6 was obtained
with oversized ellipsoids of thermal vibration for the "unsaturated" C
In agreement with the results of the
force-field calculations, 13a is remarkably stable. Even under drastic hydrogenolysis conditions, selective C-C bond
cleavage, in particular of C I - C l I to give the saturated D,,,
bissecododecahedrane,[41 could not be achieved. Drastic
dehydrogenation conditions, moreover, did not result in
(considerably endothermic) C-C bond formation between
C4 and C14 to give the "isododecahedrane" 14 (cf.
V 1 4 V I 1 , pathway C, Scheme l), which it was hoped
would occur because of the spatial proximity of the 4syn/
14syn hydrogen atoms and the 4/14 carbon atoms
(d = 1.926 and 3. I A, respectively) (Scheme 4).
20-271 cleavages have been achieved in highly strained
cyclobutane compounds under metal catalysis. That 1 remains unchanged up to 200°C in the presence of AgC104
and [Rh,(C0)4C12J is possibly explained by the weakly
exothermic course of the opening 1-6 (AAHp= -2.4
kcal/mol) and the steric shielding of the cyclobutane C-C
bonds. In such situations, the symmetry-allowed cleavage
via radical cations presents itself as a p ~ s s i b i l i t y . "Com~~
pound 1 reacted slowly with tris@-bromopheny1)ammoniumyl hexachloroantimonate (ionization at 1.05 V versus
the saturated calomel electrode) in chloroform at 20°C. A
single product was obtained (only) if an equimolar amount
of the radical cation salt was used: however, this product
A H ; = 50.2
E,, = 92.1
E,, = 98.9
Schcmr 4. A / / ' , lild At,,,
Received: January 19, 1987 [Z 2052 IE]
German version: Angew. Chem. 99 (1987) 482
[I] W:D. Fessner, H. Prinzbach, G. Rihs, Telrahedron L e u 24 (1983) 5857:
W.-D. Fessner, Disserrarion. Universitat Freiburg 1986; W.-D. Fessner,
P. R. Spurr, H . Prinzbach, J . Am. Chem. Soc., in press.
121 H. Prinzbach, W:D. Fessner. Pure Appl. Chem., in press.
131 W:D. Fessner, Bulusu A. R. C. Murty, J. Worth, D. Hunkler, H. Fritz,
H. Prinzbach, W. D. Roth, P. von R. Schleyer, A. B. McEwen, W. F.
Maier, Angew. Chem. 99 (1987) 484: Angew. Chem. I n / . Ed. Engl. 26
(1987) 452.
141 P. R. Spurr, Bulusu A. R. C. Murty, W.-D. Fessner, H. Fritz, H. Prinzbach, Angew. Chem. 99 (1987) 486; Angew. Chem. I n / . Ed. Engl. 26
(1987) 455.
151 R. J. Ternansky, D. W. Balogh, L. A. Paquette, J . Am. Chem. Sac. 104
(1982) 4503.
[6] N. L. Allinger, J. Am. Chem. Soc. 99 (1977) 8127; E. Osawa, H. Musso,
Angew. Chem. 95 (1983) I; Angew. Chem. I n / . Ed. Engl. 22 (1983) I : A.
Peyman, E. Hickl, H.-D. Beckhaus, Chem. Eer.. in press.
[7] Cf. E. M . Engler, J. D. Andose, P. von R. Schleyer, J . Am. Chem. Soc 95
(1973) 8005; J. Gasteiger, 0. Damrner, Tefrahedrun 34 (1978) 2939; R. L.
Disch, J. M. Schulman, M. L. Sablo, J . Am. Chem. Soc. 107 (1985)
[8] T. Fukunaga, R. A. Clement, J . Org. Chem. 42 (1977) 270.
191 Bulusu A. R. C. Murty, P. R. Spurr, R. Pinkos, C. Grund, W.-D. Fessner,
D. Hunkler, H. Fritz, W R. Roth, H. Prinzbach, Chimio 41 (1987) 32.
[lo] K. Alder, F. H. Flock, P. Janssen, Chem. Eer. 89 (1956) 2689; M. C.
Bohm, R. V. f.Carr, R. Gleiter, L. A. Paquette, J . Am. Chem. SOC.102
(1980) 7218
[I I ] All new compounds were characterized by their spectra ( ' H - , "C-NMR,
IR, MS) and elemental analyses.
[I21 G. K. S. Prakash, V. V. Krishnarnurthy, R. Herges, R. Bau, H. Yuan, G.
A. Olah, W.-D. Fessner, H. Prinzbach, J . Am Chem. Soc. 108 (1986)
[I31 We thank G Rihr. Ciba-Geigy AG, Basel, for the measurements.
[I41 0. Hammerich, V. D. Parker, Adc.. P/IW Org. Chem. 20 (1984) 55,
p. I15ff.
[IS] H. Prinzbach, Bulusu A. R. C. Murty. W.-D. Fessner, J. Mortensen, J.
Heinze, G. Gescheidt, F. Gerson. Angew. Chem. 99 (1987) 488; Angew.
Chem. I n / . Ed. Engl. 26 (1987) 457.
Dodecahedranes from 11.1.1 .l]Pagodanes**
By Wolf-Dieter Fessner, Bulusu A . R . C. Murty,
Jurgen Worth, Dieter Hunkler, Hans Fritz,
Horst Prinzbach,* Wolfgang D . Roth,
Paul von Rague Schleyer,* Alan B. McEwen, and
Wilhelm F. Maier*
For the conversion of [I.l.l.l]pagodane 3 into dodecahedrane 4,''.'' the catalytic, thermodynamically controlled
[*] Prof. Dr. H. Prinzbach, Dr. W:D. Fessner, Dr. Bulusu A. R. C. Murty,
Dr. J. Worth, Dr. D. Hunkler, Prof. Dr. H. Fritz
AH; = 31.4
b, X = C I j c,X=OH d,X=Br;
is not the diene 6 but the dichloride 13b (Scheme 4). Heating of a CHCl3 solution of 13b in the presence of water or
methanol results in formation of solely the crystalline diol
13c (m.p.= 193"C, 86%) or the dimethoxy compound
13e,['21respectively. Compound 13b is presumably formed
via the (opened) radical cation of l,[Is1which was detected
by ESR spectroscopy and by electrochemical methods.
I l l k C d 1 , 11101
0 VCH Verlag~gesell~chaJi
mbH. 0.6940 Wemherm. 1987
Chemisches Laboratorium d e r Universitat
lnstitut fur Organische Chemie und Biochemie
Albertstrasse 2 I , D-7800 Freiburg (FRG)
Prof. Dr. P. von R. Schleyer, Dr. W. D. Roth
Institut fur Organische Chemie der Universitat Erlangen-Nurnberg
Henkestrdsse 42, D-8520 Erlangen ( F R G )
Prof. Dr. W. F. Maier, Dr. A. B. McEwen
Department of Chemistry, University o f California
Berkeley, C A 94720 (USA)
This work was supported by the Deutsche Forschungsgemeinschaft, the
Fonds d e r Chemischen Jndustrie, the National Science Foundation
(grant C H E 940093). BASF AG. and ARRADCOM, Dover, N. J.
(USA). B. A . R. C. M. thanks the Alexander von Humboldt Foundation
for a fellowship.
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Angew. Chem. I n / . Ed. Engl. 26 (1987) No. 5
route A (see preceding communication[']) seemed promising because a considerable reduction in energy should result.i31With increasing spherical geometry, however, complications might result from the increasing difficulty in
forming carbocationi~[~I
intermediates and the hyperstability and transannular reactivity of olefinic intermediate^.[^'
metrical [4]peristylanes 7/8, which might have resulted
from the hydrogenolysis of the longest C-C bond in 3, or
the secododecahedranes 9/10 were not formed. For the
C20H24compound with C, symmetry, structure 6 seems
likely, which could be helpful in the evaluation of route
C.[31 Numerous experiments in condensed phases (treatment with Pd/C, 70 h, 300°C, ca. 1 atm H,) only lead to
1-2% of 4 from 3. Control reactions with the main product
5 gave a similarly complex product mixture, but no 4
could be detected in the gas-phase experiments and only
1-2% under solution conditions.
Encouraged by the preparation of adamantane and
other cage hydrocarbons by isomerization,[61there have
been earlier attempts to obtain dodecahedrane 4 and its
methylated derivatives from precursors like the basketene
dimer I ( n = 1) or homobasketene dimer 1 (n=2)['] or
from cyclophanes like 2.I8] However, no success was
achieved under various isomerization conditions. Attempted acid-catalyzed isomerizations of 3 also failed.
Treatment with CF3S03H (CH,CI,) led to rapid decomposition; this also occurred, but more slowly, with H z S O ~ . ' ~ ]
Under Ofah's stable ion conditions (e.g., FSO3H/SbFS,
S02CIF, -78"C), 3 was oxidized to a dication.r'O1With
diverse AIX3 Lewis acids, 3 was converted slowly into undefined products.
In initial gas-phase isomerization experiments (flow apparatus;["' Pt/Re/Alz03, Pd/C, Rh/C, Pd/Al,O3 supported catalysts; 25O-45O0C), complicated mixtures of
products (70-95%) were isolated and analyzed by G U M S .
Eventually after enrichment through crystallization, six
main components could be separated in the following order by gas chromatography:['214- 12% C2,H,, (unsymmetrical, 4 CH2, 14 C H , 2 C); 19-47% CzoHz2 ( 5 ) ; 4-25%
CzoH24, (6 CHI, 12 CH, 2 C(?)); 0.2-8% C20H24 (C,, 6 CH2,
12 CH, 2 C (?)), 1-5% C2oH26 (unsymmetrical, I CH3, 11
CH, 6 CH2, 2 C), and 0.1-2.5% C2,H2,. This last product
proved to be dodecahedrane 4 ! Of the catalysts optimized
for the conversion of cyclooctane to bicyclo[3.3.0]octane,
Pd, Rh, and Ni on various supports, as well as modified
Pd-Ti"31 and Pt-Ti catalysts, gave only very modest results,
whereas Pt/A120, brought about nearly quantitative conversion. By variation of the dispersion (D) of the platinum
(Pt foil (0% D), 25% Pt/Al,O, (2.7% D), 5% Pt/Si02 (40%
D), 0. I% Pt/AI,O, (80% D)), the reaction temperature, the
flow rate, and the composition of the carrier gas (hydrogen-helium mixtures), the yield of 4 could be increased to
8% (0.1% Pt/A1203, reduced with H2 at 360" for 1 h ; reaction conditions: 315"C, H, flow rate 0.75 mL/min, He
flow rate 2.25 mL/min, substrate temperature 25OOC). Because of its long gas-chromatographic retention time and
the remarkably downfield 'H-NMR signal (6= 3.38,
CDCI,), dodecahedrane 4 can readily be identified even in
mixtures. The 'H-/"C-NMR analysis of the other main
components leads to the conclusion that the expected symAnger, Chem. In[. Ed. Engl. 26 11987) No. 5
Schemes 1 and 2 summarize the first preliminary results
from the B route.I3] The desired saturated bissecododecahedranes,[" which could not be obtained through hydrogenation of the bisseco-dienes, became available by hydrogenolytic cleavage of appropriate cyclopropa derivatives,
11 (m.p.=295-30O0C) and 16 (m.p. >34OoC). These
could be prepared by conventional reduction ( N d t BuOH,
tetrahydrofuran (THF); 95- IOOOC) from their dichlorocyclopropa precursors."! Heating (ISOOC) a mixture of 11
with a tenfold quantity of Pd/C (10%) under 50 atm hydrogen pressure leads to complete conversion after 90 minutes. A mixture of 70-75% 12 and 5510% each of 14 and
15 could be isolated and separated by gas chromatography
(along with numerous minor components). Longer reaction times lead to the formation of more 14/15 at the ex-
Scheme I
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pense of 12. Apparently, the dehydrogenation of 12 to
give the "hyperstable" bisseco-olefin 14, which isomerizes
to 15, is efficient even under hydrogenation conditions.
Under similar conditions (20mg 16, 2 g Pd/C (lo%),
I5O0C, 20 atm H2, total conversion in 6 h), 16 gives a 2 :3
mixture (>90%) of the 1,lO- and 1,Il-dimethylbissecododecahedranes (C2h and C2, symmetry) 17 and 18, respectively.
provement of the present situation in view of the availability of 3. The limitation in the formation of 4 from 3 can
be attributed to the irreversible formation of 5, which effectively diverts the reaction from the desired course. By
substitution of the presumed bisseco intermediates 2/3 (as
described in the following communication[51)in positions
C-l,10,11,20, this competition, which is caused by transannular bond formation, can be hindered or precluded. The
formation of ca. 25% of 13 (along with 8% of 4) and ca.
25% of 19 (along with a little 4 and 20) supports this assumption.
It is hoped that various saturated bisseco precursors 21
(X=OR,NHR, C 0 2 R , etc.), with modified catalysts and
under milder conditions, will be dehydrogenated without
loss of functional groups, to give 22. Alternatively, C-C
bond formation in the bisseco precursors might be
achieved, e.g., via carbenoid intermediates or photochemical processes or by functionalization of all four methylene
positions in the pagodane skeleton.
Received. January 19, 1987 [Z 2053 IEJ
German version: Angew. Chem. 99 (1987) 484
Scheme 2.
After careful drying and degassing, 40 mg of 11 and 4 g
of Pd/C (ca. 1 : 10) were heated slowly (30 min) to 100°C
under 50 atm Hz pressure and maintained at this temperature for ca. 2.5 h. The reaction mixture was cooled, the H,
pressure was reduced to 5 atm, and the reaction mixture
was then heated slowly to 250°C and maintained for 5 h
(3 h) at this temperature. After thorough extraction, an 80%
isolated yield of a product mixture containing six components was obtained ( G U M S ) : m/z=276 (21 (20)%),
m/z=278 (5 (3)%), rn/z=278 (9 (8)%), m/z=280 (3 @)Yo),
m/z = 274 (31 (30)%), and m / z = 260 (9 (lo)%). The last two
products to be eluted could be obtained nearly pure by
fractional sublimation (8OoC, 1 torr). Complete lH-/13CN M R data[''] permitted their definite identification as the
dodecahedranes 4 and 13.'15'Heating 40 mg of 16 with 4 g
of Pd/C (10%) first under 20atm H2 pressure at 150°C
( 5 h), then under 5 atm H2 pressure at 300°C (6 h) gave,
after extraction and filtration over silica gel, 30-34 mg (7585%) of a mixture with the following main components:
m/z = 276 (29%), m/z = 290 @YO), m/z = 288 (29%),
m/z=274 (IYo), and m/z=288 YO). Comparison of the
spectra showed the first component to be 15, the third and
fifth to be the known dimethyldodecahedranes 19 and
and the fourth to be 13. Under various conditions,
20 was formed in much lower yields than 19. This suggests
that dealkylati~n"~."'(e.g., to 14 and 15) is relatively
rapid on the route from 18 to 20.
The maximal 8% yield of dodecahedrane 4 in the gasphase isomerization of 3 constitutes a remarkable im454
0 YCH Verlagsgesell.~cha}t mhH. 0-6940 Wemheim. 1987
[ I ] J . C . Gallucci, C. W. Doecke, L. A. Paquette, J Am Chem. SOC. 108
(1986) 1343, and references cited therein.
I21 P. E . Eaton, Tetrahedron 35 (1979) 2189: E. Carceller, M. L. Garcia, A.
Moyano, M. A. Pericas, F. Serratosa, Tetrahedron 42 (1986) 1831, and
references cited therein.
[31 W:D. Fessner, Bulusu A. R. C. Murty, H. Prinzbach, Angew. Chem. 99
(1987) 482; Angew. Chem. Int. Ed. Engl 26 (1987) 451.
[41 L. A. Paquette, D. W. Balogh, R. Usha, D. Kountz, G. G. Christoph,
Science 211 (1981) 575; L. A. Paquette, D. W. Balogh, J. Am. Chem. SOC.
104 (1982) 774.
(51 P. R. Spurr, Bulusu A. R. C. Murty, W.-D. Fessner, H. Fritz, H. Prinzbach, Angew. Chem. 99 (1987) 486; Angew. Chem. Int. Ed Engl. 26
(1987) 455.
I61 P. von R. Schleyer, J. Am. Chem. SOC.79 (1957) 3292; review: S. A. Godleski, P. von R. Schleyer, E. Osawa, W. T. Wipke, Prog. Phys. Org. Chem.
13 (1981) 63.
(71 N. J. Jones, W. D. Deadman, E. LeGoff, Tetrahedron Lett. 1973, 2087; J .
L. Fry, P. von R. Schleyer, unpublished results (Princeton University
1972/ 1973); P. Grubmiiller, Disserta/ion, Universitat Erlangen-Nunberg 1979.
181 K. Lammertsma, C. Brosz, 1. Thies, J. Vieth, unpublished results (Universitat Erlangen-Nurnberg 1978- 1983).
191 W.-D. Fessner, Disxertation. Universitat Freiburg 1986.
[lo] G. K. S. Prakash, V. V. Krishnamurthy, R. Herges, R. Bau, H. Yuan, G.
A. Olah, W.-D. Fessner, H. Prinzbach, J. Am. G e m . SOC. 108 (1986)
836; H. Prinzbach, Bulusu A. R. C. Murty, W.-D. Fessner, J. Mortensen,
J. Heinze, G. Gescheidt, F. Gerson, Angew. Chem. 99(1987) 488; Angew.
Chem. Int. Ed. Engl. 26 (1987) 457.
[ I I ] W. D. Roth, Disserrarion. Universitat Erlangen-Nurnberg 1984.
[I21 The new compounds were characterized by their spectra ( ' H - , "CNMR, IR, MS) and elemental analyses.
1131 L. A. Paquette, Y. Miyahara, C. W. Doecke, J . Am. Chem. Soc. 108
(1986) 1716.
1141 For example, 13: 'H-NMR (400 MHz, CDCI,): 6=3.43 (3H). 3.35
(13H), 2.91 (3H). 1.13 (CH,): "C-NMR (CDCI,): 6=75.6 (IC), 74.7
( 3 C ) , 67.2, 67.1 (7C), 66.8 (6C). 66.4 (3C), 32.6 (CH3).
[IS] L. A. Paquette, R. J. Ternansky, D. W. Balogh, W. J. Taylor, J. Am.
Chem Soc. I05 (1983) 5441.
[I61 P. Grubmiiller, W. F. Maier, P. van R. Schleyer, M. A. McKervey, J. J.
Rooney, Chem. Ber. 113 (1980) 1989.
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pagodanes, dodecahedranes
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