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Catalysed Cope Rearrangement of cis-1 2-Divinylcyclobutane.

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DSS[**] = 0).The mass spectrum shows the characteristic
main peak of tertiary aporphines (M - CHZ=N-CH~)at
mie = 256[91. The hydrochloride of (5) (C16H15N04-HC1,
m.p. 280 "C) was identified similarly. Furthermore, Nformylation, methylation, and subsequent reduction of the
formyl group yielded the naturally abundant alkaloid glaucine
(9). Thus the compound (S), which may be obtained in three
steps from papaverine ( 8 ) , provides the simplest route to
glaucine yet discovered.
Received: June 5th, 1967
[Z 524 IEI
German version: Angew. Chern. 79. 815 (1967)
by butadiene (not taken into account in the formulae given
here) and that the synthesis of (2) is thus transformed into a
synthesis of ( I ) . The product ( I ) is probably formed from
the bis-o-ally1 form (4).
i
- LgNi
- LgNi
- LgNi
[*] Prof. Dr. B. Franck and Dipl.-Chem. L.-F. Tietze
Institut fur Organische Chemie der Universitat
Neue Universitat
23 Kiel (Germany)
[l] Part 8 of Alkaloid Syntheses via Routes Similar to Biogenetic
Pathways by Oxidative Condensation. - Part 7: 171.
[2] R. Robinson: The Structural Relations of Natural Products.
Clarendon Press, Oxford 1955; E. E. van Tamelen, Fortschr.
Chem. org. Naturstoffe (Wien) 19, 242 (1961).
[3] C. Schopf and K. Thierfelder, Liebigs Ann. Chem. 497, 22
(1932).
[4] R. Robinson and S . Sugasawa, J. chem. SOC.(London) 1932,
789.
[5] J . Harley-Mason, J. chem. SOC.(London) 1953, 1465.
[6] B. Franck and G. Schlingloff, Liebigs Ann. Chem. 659, 123
(1962); B. Franck, G.Blaschke, and G. Schlinghoff,Angew. Chem.
75, 957 (1963); Angew. Chem. internat. Edit. 3 , 192 (1964).
[7] B. Franck and G . Blaschke, Liebigs Ann. Chem. 695, 144
(1966).
I81 S.M . Albonico, A. M . Kuck, and V. Deuiofeu, Liebigs Ann.
Chem. 685,200 (1965); A . H . Jackson and J . A. Martin, J . chem.
SOC.(London) I966, 2061.
[* *J DSS signilies sodium 2,2-dimethyl-2-silapentane-5-sulfonate.
[9] M . Ohashi, J . M . Wilson, I$. Budzikiewicz, M . Shamma, W .
A . Slusarchyk, and C. Djerassi, J. Amer. chem. SOC.85, 2807
(1963).
Catalysed Synthesis of cis-1,2-Divinylcyclobutane
By P. Heimbach[**I and W. Brenner[*I
cis-l,2-Divinylcyclobutane( I ) was first prepared by VogeZIll,
using a many-stage synthesis. Vogel's description of the Cope
rearrangement of this four-membered ring system to cis,cis1,5-cyclooctadiene (COD) (2) supported his hypothesis that
thermal formation of (2) from butadienegz] proceeds by
way of (I). The cis-compound ( I ) is also formed (8-17 %) in
admixture with, infer aZia, trans-divinylcyclobutane in the
photosensitized dimerization of butadiene [31. Butadiene can
by cyclodimerized faster in the presence of complexes of
zerovalent nickel that contain e.g.tris-(2-biphenylyl) phosphite
as ligand (Ni: P = 1:l), the rate being ca. 1 kg per g of nickel
in the catalyst per h at atmospheric pressure and 80 "C, and
the reaction yielding (2) (97%) and, by a side reaction, 4vinylcyclohexene (3) (2.7%) [41.
If the reaction is carried out in liquid butadiene to incomplete
conversion of butadiene, yields of up to 40 % of ( I ) , together
with (2) and (3), are obtained. The table shows the dependence of the yields on conversion of butadiene (catalyst:
Nio(C0D)Z 151 f tris-(2-biphenyl) phosphite, molar ratio 1 :1).
Conversion of butadiene (20 "C)
[ I ) , yield
We presume that, with high concentrations of butadiene, the
coordination positions o n nickel that become free on conversion of x-ally1 groups into a-ally1 groups become occupied
800
The rate of synthesis of ( I ) depends markedly o n the nature
of the ligand. With short reaction times (e.g. 0.5 h), yields
exceeding 30 % of ( I ) can be achieved even at 80 "C, although
thermal rearrangement of ( I ) to (2) has then already begun 161.
Pure (1) is obtained by distillation under vacuum: b.p. 8 "C/9
mm, ng = 1.4562[11. Substituted butadienes can also be
converted catalytically into cyclobutanes in good yields 171.
(Z 543a IE]
Received: March ZIst, 1967
German version: Angew. Chem. 79, 813 (1967)
Publication delayed at the authors' request.
[*I Dr. P. Heimbach and Dip1.-Chem. W. Brenner
Max-Planck-Institut fur Kohlenforschung
Kaiser-Wilhelm-PIatz
433 Miilheim (Germany)
[**I Paper read by P. Heimbach at Sheffield (Symposium on
AIlyIic and Olefinic Complexes of Metals) on April 11th. 1967.
111 E. Vogel, Liebigs Ann. Chem. 615, 1 (1958).
[2) K. ZiegZer and H. Wilms, Liebigs Ann. Chem. 567, 1 (1950).
[3] G. S.Hammond, N. J . Turro, and A . Fischer, J. Amer. chem.
SOC.83,4674 (1961).
[41 G. Wifke and P. Heimbach, Angew. Chem. 75, 10 (1963).
pp. 17-18; Angew. Chem, internat. Edit. 3, 105 (1963), pp. 112
to 113.
[51 B. Bogdanovit, M. Kroner, and G . Wilke, Liebigs Ann. Chem.
699, 1 (1966).
[6] P. Heimbach and W . Brenner, Angew. Chem. 79, 814 (1967);
Angew. Chem. internat. Edit. 6,800 (1967).
[7] Note added in proof (July 27th, 1967): Further investigations
have shown that cyclooctadiene and cis-l,2-divinylcyclobutane
are probably formed via the bis-x-ally1 form.
Catalysed Cope Rearrangement of
cis-l,2-Divinylcyclobutane
By P . Heimbachl**] and W. Brenner[*l
The yield of cis-1,2-divinylcyclobutane obtained on catalysed
dimerization of butadiene depends markedly on the extent of
conversion[']. This suggested that the first product ( I ) was
further catalytically aItered. Our f i s t experiments showed
that predominately cis,cis-l,5-cyclooctadiene (Z), with little
4-vinylcyclohexene (3), is formed from ( I ) . The rate of the
catalysed rearrangement of ( I ) could be determined a t 24 "C
by following the volume contraction and the change of refractive index during the reaction, as well as by gas-chromatographic analysis. The concentration of catalyst in the solution
was 0.2 or 0.1 molar (Ni:ligand = 1 :1). The rate is directly
dependent on the Ni concentration and the nature of the
ligand up to ca. 97 % conversion of ( I ) .
Fig. 1 shows the rate of the catalysed (24 "C) and also of the
thermal (uncatalysed) rearrangement (80 "C) of ( I ) to (2).
Angew. Chem. internal. Edit.f Vol. 6 (I967) / No. 9
Trebellns e f al. [*I recently described the first Cope rearrangement that is induced by transition-metal compounds and yet
occurs stoichiometrically. The catalysed Cope rearrangement
of (1) and the fact the bis-ally1 complexes formed as intermediates therein can react with further components are
phenomena of a new type. We are engaged in analogous
studies of other 1,5-dienes with nickel and other transitionmetal catalysts.
Received: March 21st. 1967
[Z 543b IE]
German version: Angew. Chem. 79, 814 (1967)
Publication delayed at the author's request.
5
"0
[*I Dr. P. Heimbach and DipLChem.
W. Brenner
Max-Planck-Institut fur Kohlenforschung
Kaiser-Wilhelm-Platz
433 Miilheim (Germany)
[**I Paper read by P. Heimbach at Sheffield (Symposium on
Allylic and Olefinic Complexes of Metals) on April llth, 1967.
[l] P. Heimbach and W . Brenner, Angew. Chem. 79, 813 (1967);
Angew. Chem. internat. Edit. 6, 800 (1967).
121 G. Wilke and P. Heimbach, unpublished.
131 Paper read by P. Heimbach at the GDCh Conference, Bonn,
September 1965.
141 B. Bogdanovic, M . Kroner, and G. Wilke, Liebigs Ann. Chem.
699, 1 (1966).
[5] G. Wilke, E. W . Miiller, and P. Heimbach, Angew. Chem. 75,
10 (1963), pp. 17-18; Angew. Chem. internat. Edit. 3,105 (1963),
pp. 112-113.
[6] G. Wilke and P. Heimbach, Angew. Chem. 75, 18-19 (1963);
Angew. Chem. internat. Edit. 3, 113-114 (1963).
[I] H. Breil, P. Heimbach, M . Kroner, H. Miiller, and G . Wilke,
Makromolekulare Chem. 69, 18 (1963).
181 J. C. Trebellas, J. R . Olechowski, and H. B. Jonasserr, J. organomet. Chem. 6,412 (1966).
15
10
Thermal conversion of ( I ) at 80 "C.
-x-x-
..
Catalysed rearrangement, 24 "C, 0.2 M solution; ligand, tris(2-biphenylyl) phosphite. . . Catalysed rearrangement, 24 OC, 0.1 M
solution; ligand, tris-(2-biphenylyl) phosphite. - - - Catalysed rearrangement, 24 OC. 0.2 M solution; ligand, triphenylphosphine.
Ordinate: % rearranged ( I ) .
Abscissa: Time (hours).
The latter is a first-order reaction whereas the catalysed rearrangement is a zeroth-order reaction with respect to ( I ) .
However, the marked dependence of the composition of the
product o n the nature of the ligand [tiis-(2-biphenylyl)
phosphite, 0.5 % of (3), 99 % of (2); triphenylphosphine,
31 % of (3), 60 % of (2); tricyclohexylphosphine, 33 %
of (3), 55 % of (2)] confirms the assumption that the reactivity of the bis-x-ally1 form (4) increases with marked
back-donation of the nickel to the free d orbitals of the phosphorus (phosphite), but that the reactivity of the n-allyl-0allyl form (5) is greater when there is weak back-donation
(phosphine) 12331.
5
Lg-Ni
1-
Lg-Ni
1-
Lg-Ni
* I -.
-b C=C
Lg-Ni
(a] The prefixes cis and trans refer to the configuration of the allyl
groups between the C-atoms 2 and 3, or 6 and 7.
[ b ] In this case, Lg = isoprene.
+C=C
I
-Lg-Ni
L-
Ni
Structure of Alkali MetaI t-Butoxides
By E. Weiss, H . Alsdorf, and H . Kiihr[*]
The or-w-ally1 cg chain that is formed from ( I ) as intermediate o n the Ni(o)-Lg system apparently exists in equilibrium with various other forms.
Only the forms (4) and (5) react in the catalysed rearrangement of ( I ) t o (2) and (3). If ethylene is added to the reaction
mixture [ca. 45 atm, 20 "C, Lg = P(C6H5)3], of cis,trans-1,5cyclodecadiene [from (6) + ethylene] (73 %) and trans-1,4,9decatriene [from (7) + ethylene)](l%) are formed, as well as
(2) and (3). Isoprene reacts with ( I ) in the presence of, e.g.,
cyclododecatrienenickel(0) 141 with formation of frans, fruns,
frans-l-methyl-l,5,9-cyclododecatriene[from (8) and isoprene]. These reactions support the assumption that a c8
chain is formed as intermediate in the synthesis of eight- [51,
ten- [61, and twelve-membered rings [71 o n complexes of
nickel(0) 121.
Angew. Chem. internat. Edit. / VoI. 6 (1967)
No. 9
According to X-ray powder studies, the t-butoxides of
potassium, rubidium, and cesium are tetrameric. They have
cubic lattices, each unit cell containing one tetrameric
formula-equivalent [space group P43m, 00 = 8.475 8, (K),
8.610 (Rb), 8.902 (Cs)]. The tetrameric structural units have
T d symmetry, the metal and oxygen atoms occupying alternate corners of a n only slightly distorted cube with the four
t-butyl groups lying o n the extended diagonals (see Fig. 1).
The following atomic distances were obtained for the
potassium compound: K-0 2.56; C-0 1.39; C-CH3 1.56A;
112.1O . The non-metallic atoms
bond angle 0-C-CH3
could not be precisely located in the rubidium or cesium
compound. Sodium t-butoxide crystallizes in a lattice of
lower symmetry and as yet undefined structure.
80I
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