close

Вход

Забыли?

вход по аккаунту

?

Eliminations from Three-Membered Rings Cyclopropylcyclopropene and Bicyclopropylidene from 1-Chiorobicyclopropyl.

код для вставкиСкачать
at a distance of ca. 16.5A. The volume occupied by the
anion in the direction of the six neighboring ions (determined on a model of the structure here proposed) is sufficiently small to avoid any overlap therewith. The macroisopolyanion takes four molecules of water of crystallization
into its interior, while the remaining 76 molecules of water
of crystallization fill the space between the anions.
Mathematical analysis of potent iometric equilibrium w v e s
fi)r rhe system H+/MoO;-: By a mathematical analysis
of the Z,logh[I6] equilibrium curves for the system
H '/MOO;-, Sasuki and Sille'n[' 'I deduced for large values
of Z the existence of a large anion of probable formula
Mot,02; (Z' =34/19= 1.79). Using their data we
have calculated that a set of species in which the 34,19-ion
is replaced by a 64,36-ion would give only slightly less
good standard deviation of 2 (Table 1); and in this connection it should be noted that the calculations become increasingly better for the 64,36-ion as the concentration is increased. Susaki and Sillhn's measurements thus do not run
counter to the results of our investigations.
Eliminations from Three-Memkrd Rings:
Cyclopropylcyclopropene and Bicyclopropylidene from l-Chlorobicyclopropyl[**I
By Lutz Fitjer and Jean-Marie Conia[*]
Bicyclopropylidene ( 4 ) has a key position in the chemistry
of polycyclopropylidenes ([n]-rotanes)[" as the direct precursor of tricyclopropylidene ([3]-r0tane)'~' and tetracyclopropylidene ([4]-r0tane)[~].
( 4 ) can be obtained by cyclopropanation of dimethyleneallene131 or by anionic dimerization of cyclopropene (1)
by metal amides in liquid ammonia with subsequent
isomerization of the cyclopropylcyclopropene ( 2 ) by way
of the allylic anion ( 3 ) [ " ' .
Received: December 18, 1972 [Z 775 IE]
German version: Angew. Chem. 85. 305 (1973)
[I] 0.Glemsrr, W Holznagrl, W Hiiltje, and E. Schwarzmann, 2. Naturforsch. 20b, 725 (1965); 0. Glemser, W Holmagel, and S I . Ali, ihid.
XJb, 192 (1965); 0.Glemsrr and K H . Tytko, ihid. 246, 648 (1969);
K . H . 3 t k o and 0. Glemser, ibid. 25 b, 429 (1970).
[2] All thedata for concentration, including those for the polymolybdate
ions, refer t o Mo. A solution of, r g., a species Mo,Oe; that is 1 M
in this sense contains 1/7mol of Mo,O'& per I.
[3] By the degree of acidity Z of a solution is meant the molar ratio
of rrocrnl H * to M O ? . applied inirialli..
[4] Measurements were performed on a CODERG PH I Raman spectrometer combined with an OIP 181 E 200 mW-He-Ne-laser.
[5] If for a solution appropriate steps are taken to obtain linearity
between the concentration of a species and the intensity of its Raman
spectrum, intensity difference diagrams can be used in the same way
as extinction difference diagrams in absorption spectroscopy [6] for
clarification of the course of chemical reactions.
The preparative value of the isomerization of (2) to ( 4 )
remained, however, limited because of the poor availability
of cyclopropene ( I )Is1
and the poor yield in the dimerization["].
We have therefore tried to prepare (2) by elimination
of hydrogen chloride from I-chlorobicyclopropyl ( I 2).
[6] K . H . Tvrko, Dissertation, Technische Hochschule Aacben 1967;
H. Mausrr, 2. NaturTorsch. 23b, 1021, 1025 (1968).
[7] By "molybdenum fraction" we mean the amount of molybdenum,
expressed a s a fraction, ih the species under discussion.
[S] By 2' value of an isopolyion we mean the ratio of the stoichiometric
coefficients of H' and M O i - in the overall equation of formation of
the isopolyion.
[9] K . H . q , r k o and 0. Glrmsrr, Chimia 23, 494 (1969); 2. Naturforsch.
26h, 659 (1971); K . H . Tvtko, Angew. Chem. 83, 935 (1971); Angew.
Chem. internat. Edit. 10, 860 (1971); Lecture at Heidelberg 1972, and
at the 1st Meeting, International Society for the Study of Solute-SoluteSolvent Interactions, Marseille 1972.
f i e 3 7 5 7 0
OSOCl
[t-yl
[lo] I . Lindqcisr, Nova Acta Regiae SOC.Sci. Upsal. Series IV. 15, NO.
I (1950).
1"
[I I] The apparent molecular masses M,,, must be corrected in two
respects in order t o yield true molecular masses: M,,, is t o be extrapolated
t o c = O (this gives (MaDJ0), and that value must be further corrected
in respect of the charge.
[I21 The Na ' ions take part in the packing, analogously to ammonium
polymetalates [131.
[I31 R . Allmann, Acta Crystallogr. B 27, 1393 (1971); I . Btischen, B.
Buss. and B. Krebs, t o be published.
[I41 X-ray investigation ofthe Ba, Na, and NH, salts of the 36-molybdate
ion gave a triclinic unit cell for the BA salt. For the Na salt (the NH,
salts are isotypic) several monoclinic species were found whose diffraction
patterns were the same o r very similar. Analogous calculations and
considerations (see above and the structural proposal) lead to an almost
identical distribution of the 36-molybdate ions in the unit cell. Further
investigation is in progress.
[15] Y Sosaki, I . Lindqoisr, and L. G. Sillin, J . Inorg. Nucl. Chem.
9, 93 (1959); Y Susaki and L. G. Sillin, Acta Chem. Scand. IS, 1014
(1964); Y Sasaki and L. G . Sillin, Ark. Kemi 29, 253 (1968).
1161 h = H' concentration at equilibrium.
[I71 Wethank Dr. W Biihr, MPI fur BiophysikalischeChemie,Gottingen,
for his help with this part of the investigation.
332
100%
p]
Dr. L. Fitjer and Prof. Dr. J. M. Conia
Laboratoire des Carbocycles
Universite de Paris-Sud
F-91 Orsay (France)
[**I This work was supported by the Deutsche Forschungsgemeinschaft
through award of a research grant (L. F.).
Angrw. Chrm. inrernur. Edif. i Vol.
I2 11973) i No. 4
The sodium amide used in this reaction could effect both
the elimination to give (2) and the subsequent isomerization to (4)I'l.
Starting from cyclopropyl methyl ketone ( 5 ) , we have
made 1-chlorobicyclopropy1 ( 1 2 ) [ s iaccessible by two independent routes:
1. By geminal dihalogenation to give (1,l-dichloroethyl)cyclopropane (7)[Io1, elimination to give (I-chlorovinylfcyclopropane (9)" 'I, addition of dibromocarbene, with phenyl(tribromomethyl)mercury as carbene precursor[' to give
2,2-dibromo- I -chlorobicyclopropyl ( I 1), and selective
reduction with tri-n-butylhydridotin[131
to give ( 1 2 ) ; and
2. by reaction of the sodium enolate of ( 5 ) with trimethylsilyl chloride to give [1-(trimethylsilyloxy)vinyl]cyclopropane ( 6 ) [141, cyclopropanation by a modified SimmonsSmith reaction1 ' 5 1 to give I-(trimethylsilyloxy)bicyclopropyl (a), conversion into the chlorosulfite ( 1 0 ) (not isolable
but detectable spectroscopically), and pyrolysis to give
(12). The 2-cyclopropylallyl chloride ( 1 3 ) contaminating
(12) can easily be removed by addition of bromine.
The reaction sequence ( 8 ) -+ (10) + (12) is, to our knowledge, the first example of replacement of a trimethylsilyloxy group by chlorine.
The formation of a preponderant amount of ( 1 2 ) rather
than of ( 1 3 ) in the pyrolysis of (10) is further evidence
of the relative stability of the 1-cyclopropylcyclopropyl
cation ( 1 4 ) . This ion undergoes only slight ring opening
to 2-cyclopropylallyl cation (15)[t61.
The subsequent elimination of hydrogen chloride from
I-chlorobicyclopropy1 ( 1 2 ) can be effected without any
side reaction by using sodium amide in liquid ammonia
Table 1. Physical and spectroscopic data for compounds (6), ( 8 ) , ( I 1 ),
and ( 1 3 ).
~
B. P
[ C/torr]
I R [a]
[cm- '1
145/760
3114,3092,3012
2960,2900
vc:-;(. 1648
65/23
'H-NMR [b]
1 [PPml
_ _ _ . . _ ~ ~ ~ ~
vC-H
vc ....
+, 3082,3006,2956
2896
52/0.015
[cl
vC--,, 3085,3011
vc - H
vc-=c
3083,3004.2950
1642
d5.98(1)(5=1 Hz),
d 6.1 I ( I ) ( J = 1 Hz),
m 8.45-8.90( I),
m 9.35-9.65 (4),
s 9.82 (9)
m8.50-9.10(1),
m 9.40-9.80 (8),
s 9.90 (9)
s 8 21 (2),
m8.25-8.70(1),
m 9.05---9.75 (4)
q 5.03 (l)(J= 1 Hz),
t 5 2 3 ( 1 ) ( J = 1 Hz),
d6.01(2)(5=1 Hz),
m 8.30-8.90(1),
m 9.10-9.50 (4)
__
-__.__
~
[a] Characteristic IR frequencies. measured for pure liquids.
[b] Measured for CCI, solutions with T M S a s internal standard.
[c] Purified by gas chromatography; (13) cannot be separated from
( I 2 ) (b.p. 75 'C/150torr) by distillation.
A n g m . Clrmfi.~nrrrtiar.Edit. / W. 12
( IY73)
;No. 4
and leads to bicyclopropylidene ( 4 ) via cyclopropylcyclopropene (2). In agreement with this interpretation the
product ratio ( 4 ) / ( 2 ) increases greatly on prolongation
of the reaction time; after 18h we obtained 15% of ( 2 )
and 52% of ( 4 ) . Subsequent distillation afforded 40%
of pure bicyclopropylidene ( 4 ) , b. p. 101 "C, with complete
polymerization of ( 2 ) . It is to be expected that the yield
of ( 4 ) can be further increased1t8!
(2) could be unambiguously identified in admixture with
( 4 ) by means of its characteristic methine-proton signal
[t=4.10ppm, J = 3 H z (pentane)]. The spectroscopic data
for (4)[']',(7)['Oh1, (Y)[loal and ( 1 2 ) l y 1 were in accord
with those reported in the literature.
All the new compounds gave satisfactory analytical values.
Their most important physical and spectroscopic data are
collected in Table 1.
We prefer the synthesis by way of (6): it permits ( 4 )
to be obtained on a preparative scale by use of commercially available reagents.
Received: December 29, 1972 [Z 783a lE]
German version: Angew. Chem. 85, 347 11973)
[l] J. L. Ripoll, J. C . Limasset, and J. M . Conia, Tetrahedron 27, 2431
(1971), and literature cited therein.
[2] L. Fitjer and J. M . Conio, Angew. Chem. 85, 349 (1973): Angew.
Chem. internat. Edit. 12. 334 (1973)
[3] P . LePerchec and J. M . Conia, Tetrahedron Lett. 1970, 1587.
[4] A. J . Schipperijn, Rec. Trav. Chim. Pays-Bas 90, 1 I10 (1971).
[5] G. L. Closs and R. D . Krantz, J. Org. Chem. 31. 638 (1966).
[6] Eliminations from thi-ee-membered rings with subsequent double
bond migration t o the exo-position are known [7]. The bases used
hitherto were almost exclusively alkali-metal alkoxides (sodium hydrideethanol in ether [7a], potassium isopropoxide [7b, d], and potassium
rerr-butoxide [7c, e-h] in DMSO).
[7] a) J. A. Carbon, W B. Murrin, and L . R. Swett, J. Amer. Chem.
Soc. 80, 1002 (1958); b) 7: C. Shields, B. A . Shoulders, J . F . Krause,
C. L. Osborn. and P . D. Gardner, ibid. 87, 3026 (1965); c ) C . L . Oshorn,
7: C. Shields, B. A . Shoulders, J . F. Krause, H . I.' Cortez, and P. D.
Gardner, ibid. 87. 3158 (1965): d ) 7: C . Shields and P . D. Gardner, ihid.
89, 5425 (1967): e) 7: t.Shields and W E . Billups, Chem. Ind. (London)
1967, 1999; f) M. Berfrand and H . Monri, C. R Acad. Sci. Paris C
264, 998 (1967); g) 7: C . Shields, W E . Billups, and A. R. Leple!,, 1.
Amer. Chem. SOC.YO, 4749 (I968); h) M! E w i a n n and M . Hunuck, Tetrahedron Lett. 1Y72, 4213.
[8] I-Chlorobicyclopropyl f 121 was first obtained by Landgrebe and
Becker [9] by photochlorination of bicyclopropyl, but could not be
separated from the (I-chloroethy1)cyclopropanealso formed.
[9] J. A . Landgrebe and L. W Becker. J . Amer. Chem. SOC.89. 2505
11967); 90, 395 11968).
[lo] a ) M. Hanack and 7: Biisskr, J. Amer. Chem. SOC.Y1, 2117 (1969);
b) C . E . Hudson and N. L. Bauld, ibid. 94, 1158 (1972). An almost
quantitative yield of ( 7 ) is obtained when the free hydrogen chloride
in a suspension of phosphorus pentachloride in methylene dichloride
is bound by 0.1 equivalent of pyridine before addition of ( 5 ) .
[I I ] Short heating of equivalent amounts of ( 7 ) and quinoline suffices
t o effect the elimination. Use of potassium hydroxide in triethylene glycol
[loa] offers no advantage over this.
[I21 D. Sei:ferrh and R. L. Lamberr j r . , J. Organometal. Chem. 16, 21
(1969); see also D . Suyferfh, Accounts Chem. Res 5 , 65 (1972). and
literature cited therein.
[I31 D. Sej:ferrh, H . Yamazaki, and D . L. Allesron, J. Org. Chem. 28,
703 ( 1963).
[I41 The methods used for preparation of trimethylsilyl enol ethers
[for a review see: H . 0. House, L. J . Czuhu, M. Gall, and H . D. Olmsteud,
J. Org. Chem. 34. 2324 11969)] essentially differ only as concerns the
type of base used for formation of the enolate. Sodium amide has the
advantage over the bases used previously that ammonia and sodium
chloride are the only products accompanying the desired enoi ether.
Filtration and removal of the solvent (ether) suffice for isolation of
the crude e n d ether.
L15J J. M . D W I ~ SC.
, Girord, and J. M . Cotzia, Synthesis IY72, 549.
[I61 Cf. also the results of solvolyses with I-chlorobicyclopropyl [9],
I-itosvloxv)bic~clopropylr17al. 2.2-dideuterio-I-(tosyloxy)bicyclopropyl [ 17 b], and (tosyloxymethy1)spiropentane[ 1 7 ~ 1 .
333
1171 a ) 5. A .
Howelf and J . G Jwerr, J. Amer. Chem. Soc. 93, 798
(1971); b) K. A . Muriin and J . A . Lmrigrrhe. J. Org. Chem. 37. 1996
(1972): c) J . J . Ga/nrskr and J . P. Ohurdic~r,_I Amer. Chem. Soc. Y4,
6053 (1972).
1181 Nofe added in proof(March 15, 1973): A 55% yield of pure ( 4 )
could be obtained by treatment of ( I 2 ) wiih potassium rw-butoxide
in DMSO.
Tricyclopropylidene ([3]-Rotane)[**]
By Lutz Fitjer and Jean-Marie Conial']
Polycyclopropylidenes ([nl-rotanes) ( I ) [ I 1 are of particular
interest because of the question whether their cyclopropane
rings, which are linked to one another in x i s fashion
without interruption, could lead to an electron system
delocalized over the central ring.
A qualitative assessment on the basis of the "bent-bond"
model for cyclopropane12' shows that this delocalization
becomes the more probable the smaller the angle (6)
between the planes of two neighboring cyclopropane rings
and the greater the p contribution to the cyclopropane
hybrid orbitals directed from C-1 to C-2 and from C-1
to c-3.
(I), n
=
3, 4 , 5 . .
We report here the synthesis of tricyclopropylidene ( f ).
n= 3, and show, by spectroscopic comparison with dispiroheptane (2), spiropentane ( 3 ) , and cyclopropane ( 4 ) that
for ( I ), n = 3, a delocalization of the cyclopropane hybrid
orbitals over the central ring is to be excluded.
Tricyclopropylidene ( I ) , I ) =3, could be obtained by spiroalkylation of bicyclopropylidene ( 5 ) " ) with I-cyclopropyl-l-nitrosourear6]as source of cyclopropylidene. Spiroalkylations of that type are known"' but have hitherto been
carried out in presence of a large excess of olefin. We,
however, used an excess of kyclopropyl-1-nitrosourea
and obtained a 30% yield of the desired tricyclopropylidene
(J), along with allene.
The compounds ( 2 j r x 1and ( 3 ) required for comparison
were prepared by CuCI-catalyzed reaction of ( 5 ) with
diazomethane~'"]and according to ref. [ I I], respectively.
.
Thus the conditions for a possible delocalization are most
favorable for hexacyclopropylidene ([6]-rotane) ( I ), n = 6
@=60 , hybridization C-1, C-2=C-l, C-3=sp5) and least
favorable for tricyclopropylidene ([3]-rotane) ( I ), n= 3
(S= 120-, c-1, c - 2 = c-I , c - 3 =sp3[3')14l.
In spite of the expected high strain energy, pure tricyclopropylidene ( I ) , n= 3 (m. p. 29-31 .C),is thermally extremely
stable. Heating for an hour at 3 0 C does not lower
its melting point, and the substance decomposes only at
about 350 C.Its structure is proved by spectroscopic data
(see Table I).
Table I Spectroscopicdata for the compounds ( 4 1 , ( 3 1 , ( 2 ) , and ( 1 ) .
14)
131
(7)
(/i,n=3
3081 [I31
301 3
3080
301 2
3062
2980
s9.87[14]
9 78 [15]
s 9.24
s 9.24
s 8 85
3060
2982
187.4 178 4
161.8 [I41
162 tZ [ 161
1 59.8 [141
162~3
160&2[g]
188.0 1745
162i2
196.3 [16]
195.7 [17]
186.8
IS6 8 180.9
m 9.30 [q 179.0
s 9.34
11=3
232.0 (42)
201.5 (15 )
209.5 (161
762 ( 3)
105.0(3O)sh
21 2.5 (34)
262 ( 2 )
[a] Measured for CCI, solutions, except for ( 4 ) (capillary).
[b] Measured for CCI, solutions with T M S as internal standard
[c] Proton decoupled specira; measured for C I X I , solutions with TMS as internal standard. The chemical
shifts obtained were converted to CS, as standard by using the relation S(CS,)=G(TMS)+ 192.8 [18].
[d] Taken from non-decoupltd "C-NMR spectra: the relatively large range of error I S ascribed to the complexit)
of the spectra caused by '"C--C -H long-range couplings.
[el Measured for cyclohexane solutions; sh =shoulder.
[fl Center of an AABB' line sysrem wiih v, - vli s0.2Oppin.
[g] (.J13C-H)h: (J"C-H)., could not be determined because the number of accumulations was to<) small.
~~
[*I
Dr. L. Fitjer and Prof. Dr J. M. Conia
Laboratoire des Carbocycles
Universite d e Paris-Sud
F-91 Orsay (France)
[**I Etude des Rotanes, Part V. Part I V : [ I el. This uoi-k was supported by the Deutsche Forschungsgerneinschaft by award of a research
grant (L. F.). We thank Jeolco Ltd., Grove Park-Edgware Road. London.
N. W. 9. for determining the "C-NMR spectra.
Because of the low intensity of the molecular ion ( < 1 %)
we have determined the exact mass of M - I , which is
characteristic for many cyclopropane derivatives' ' ". Calculated ( 1 19.086)and experimental values (1 19.086&0.002)
showed the expected agreement.
Whether tricyclopropylidene( I ), n=3, possesses a deiocalized electron system can be decided by comparison of
Документ
Категория
Без категории
Просмотров
0
Размер файла
321 Кб
Теги
elimination, cyclopropylcyclopropene, chiorobicyclopropyl, bicyclopropylidens, membered, ring, three
1/--страниц
Пожаловаться на содержимое документа