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Thermal rearrangement of some [1.1.1] propellanes
Tetrahedron Letters,Vo1.27,No.48,pp Printed in Great Britain
THERMAL
REARRANGEMENT
Johannes Institut
KarlstraBe
Summary:
Thermal isomerization
a 3:2 mixture
Whereas ponding
the thermal
der Universitat
behavior
of the
1 in a flow system at 370°C led to
(5) = and 6-vinylidenebicyclo[3.l.O]hexane into 1,2-divinylcyclopropene
the chemistry 2
(l), and,
(2).
can now be easily
established.
Miinchen
Miinchen 2, Germany
2 and 2 were converted
into dimethylenecyclopropane
fully
[~.~.~]PROPELLANES
of [1.1.f]propellane
bicyclo[l.l.O]butanes,l
not yet been
Chemie
23, D-8000
[l.l.l]propellanes
oo40-4039/86 $3.00 + .OO Perqamon Journals Ltd.
and Giinter Szeimies*
of bicyclo[5.l.O]octa-1,6-diene
($1. At 430°C, propellanes respectively,
OF SOME
Belzner
fiir Organische
5839-5842,1986
Here we wish
[l.l.l]propellanes
synthesized
of this
from the corres-
intriguing
to report
on results
4, 2 and the parent
3. =
A
5839
system
has
concerning hydrocarbon
A solution in a
14O'C
1 H NMR
of J in C6D6,
bath
and the decrease
spectroscopy.
some polymeric
thermal traces At
of 2,
3
of unknown the
material Better
signals
into the thermal
at 37O'C.
The condensed
through
this mixture
(2) was
the only product.
of the Rh(1)
ion catalyzed
not be the product
in a process
pyridine-d5
to the diene
spectroscopic
behavior
after
of the
catalyzed
was chosen
9 hours,
by
as solvent.
but only polymer-
consisted
5, _ which
These
on further
if a small portion data
of 2 and 5 are
raised system,
indicate
heating
in accord
furnace
of i, 2 and 5. of 5 at
1 was cleanly
converted
that,
at 37O"C, the allene
be formed with
from
L rear5. At preA bypassing
the proposed
tures.
A / \ 9 II
/0\ 6 I
13
2 was
the proportion
affords
of 5 could
when
in an electric
of a 1:6:4 mixture
in the flow results
of ; was obtained, tube placed
to the same procedure
of l and = 5. At 420°C
it is not clear
2. The
be formed
a 40 cm Pyrex
material
into $ as the sole product.
sent
that 2 might
of J had vanished
by
of i had disappeareel. Besides
component
Therefore,
was kept
formed.
at 0.1 torr
ranges
arose
of J, but might
distilled
the expense
as the major
electrophiles.
insight
Subjecting
the signals
nitrogen,
of 1 was monitored
bicyclo[4.2.0locta-1,6-diene
suspicion
'H NMR was
in an NMR tube under
of the concentration
30 min.,
observed
rearrangement
14O"C,
ic
After
material,
As f had also been isomerization
sealed
14
struc-
5841
Unlike at 370°C. was
2, the propellane However,
isolated.
stored
to give
of the product
$j is the result
system
at 43O"C,
product.
be recognized
of the central
contrast, respect would
the concerted to orbital
diene
2. Under
versible.
Breaking
forcing
reaction
the C-6-C-7
a new C-C bond between
affording
bond
Bicyclo[4.l.O]hepta-1,5-diene 2, which diene
is formed
is an intermediate
could
In
with
undergo
a dimethyl-
11) the more
the allene
seems
from
stable to be re-
Jz and forming
6.
precursor
ring-opening
directly
6
[02s + u2al path
the diradical
(13) is the obvious _=
if 12 is produced
lead to 2.
this process
of Jp to give
can
of 1, 2 and 2.
be unfavorable
(via diradical
from 12 by an electrocyclic
.5, it is not clear,
could
favorable
VI, which
yield
framework
isomerization
conditions,
C-2 and C-6 could
in the flow (2) as the only
[l.l.l]propellane
The
intermediate
the
5
of J into 2 should
considerations.
rearrangement7 more
of the
2 isomerized
seem to suggest
of 2. Indeed,
[02s + o2a] process
conversion
be
of this reaction,
observations
of the thermal
allowed
lead to the short-lived
enecyclopropane
spectra.
C-C bond
(2)
2 showed
it could
into dimethylenecyclopropene
feature
symmetry
data.
[l.l.l]propellane
isomerization
by its NMR
symmetry
nitrogen,
(8).4 The low temperature
2 was converted
2, an orbital
that at 114°C
of a catalyzed
as a common
1,2-divinylcyclopropene
a week.
and our above-mentioned
2 was identified
Retention
For
reported
of the flow pyrolysis
on its spectroscopic
But in C6D6 under
for at least
3-methylenecyclobutene
structure
of 2 and
for 2 rests
to polymerize.
it has been
the conditions
a I:3 mixture
proof
in the refrigerator
Recently
that
at 430°C
Structure
a high propensity
1 withstood
of the triene
reaction.
As with
2 or if the diene
29
in this process.
Acknowledgement This Fonds
work
was
supported
der Chemischen
by the Deutsche
Industrie.
Forschungsgemeinschaft
and by the
5842
Table
4:
1. NMR Data
'H (C606):
'3C (C6D6):
5.80 (broad s, 1 H).
23.44,
'H (C6D6):
(4 t), 109.37,
14.15, 27.08 (2 t), 35.08
125.91 (2 d), 141.36,
148.72 (2 s).
(2 C, t), 116.73 (d), 119.28 (s).
'H (C6D6): 0.99 - 1.80 (m, 6 H), 2.06 (m, 2 H), 4.67 (m, 2 H). 13C (C6D6): 20.90
I:
23.75, 24.44, 37.01
1.05 (s, 2 H), 1.80 (m, 2 H), 2.32 (m, 4 H), 5.70 (m, 2 H).
13C (C606): G:
(6 Values)
1.38 - 1.75 (m, 2 H), 1.83 - 2.19 (m, 4 H), 2.91 - 3.14 (m, 2 H), 5.14 (t,
J = 4 Hz, 1 H),
5:
of 2 - 2 and 2
(t), 26.96
(d), 29.17
(2 C, t), 75.54 (t), 81.75,
194.79 (2 s).
’ H (C6D6): 1.18 (s, 2 H), 5.25 (dd, J = 2 Hz and J = 9 Hz, 2 H), 5.38 (dd, J = 2 Hz and J = 17 Hz, 2 H), 6.46 (dd, J = 9 Hz and J = 17 Hz, 2 H). 13C (C6D12): identified
2:
5.62,
122.60
(2 t), 125.35
(d); the signal of C-l and C-2 could not be
with certainty.
'H (Et20): 1.58 (m, 2 H), 5.27 (m, 2 H), 5.50 (m, 2 H). 13 C (Et20/CDC13): 101.38 (t), 124.80 (s); the signal of C-3 could not be identified
with
certainty.
References: Semmler,
G. Szeimies
I)
K.
2)
K. B. Wiberg, H. Huber, (1985). M.
E. Heitbronner,
K. B. Wiberg,
D. Newton,
-ibid.
J. Belzner
4)
K. B. Wiberg
5)
R. Bloch,
P. Le Perchec
Ed.
2, 798
6)
R. B. Woodward 5, 781
7)
and
J. Am.
K. Laidig,
W. P. Dailey,
7247
G. Szeimies,
and
J. Belzner, and
W. P. Dailey, IQI, -__
3)
Engl.
and
S. T. Waddell
and
Sot.
K. B. Wiberg,
F. H. Walker,
l_OZ, 6410 --_
Lett.
1986,
J. Am.
S. T. Waddell,
(1985). 1553.
Chem.
E. Honegger,
Sot.
101, _--
L. S. Cracker,
7172 and
(1985).
unpublished.
F. H. Walker, and
Chem.
Tetrahedron
J. Am.
J.-M.
Chem.
Conia,
Sot.
Angew.
Lpi, Chem.
5239 gz,
(1982). 810
(1970);
Angew.
Chem.,
Int.
(1970).
and
R. Hoffmann,
Angew.
Chem.
&
797
(1969);
Angew.
Chem.,
Int.
Ed.
Engl.
(1969).
J. J. Gajewski, Toronto,
(Received
Sydney,
"Hydrocarbon San
Thermal
Francisco,
in Germany
1981,
8 September
Isomerizations", pp 77 - 80,
1986)
and
Academic references
Press;
New
therein.
York,
London,
THERMAL
REARRANGEMENT
Johannes Institut
KarlstraBe
Summary:
Thermal isomerization
a 3:2 mixture
Whereas ponding
the thermal
der Universitat
behavior
of the
1 in a flow system at 370°C led to
(5) = and 6-vinylidenebicyclo[3.l.O]hexane into 1,2-divinylcyclopropene
the chemistry 2
(l), and,
(2).
can now be easily
established.
Miinchen
Miinchen 2, Germany
2 and 2 were converted
into dimethylenecyclopropane
fully
[~.~.~]PROPELLANES
of [1.1.f]propellane
bicyclo[l.l.O]butanes,l
not yet been
Chemie
23, D-8000
[l.l.l]propellanes
oo40-4039/86 $3.00 + .OO Perqamon Journals Ltd.
and Giinter Szeimies*
of bicyclo[5.l.O]octa-1,6-diene
($1. At 430°C, propellanes respectively,
OF SOME
Belzner
fiir Organische
5839-5842,1986
Here we wish
[l.l.l]propellanes
synthesized
of this
from the corres-
intriguing
to report
on results
4, 2 and the parent
3. =
A
5839
system
has
concerning hydrocarbon
A solution in a
14O'C
1 H NMR
of J in C6D6,
bath
and the decrease
spectroscopy.
some polymeric
thermal traces At
of 2,
3
of unknown the
material Better
signals
into the thermal
at 37O'C.
The condensed
through
this mixture
(2) was
the only product.
of the Rh(1)
ion catalyzed
not be the product
in a process
pyridine-d5
to the diene
spectroscopic
behavior
after
of the
catalyzed
was chosen
9 hours,
by
as solvent.
but only polymer-
consisted
5, _ which
These
on further
if a small portion data
of 2 and 5 are
raised system,
indicate
heating
in accord
furnace
of i, 2 and 5. of 5 at
1 was cleanly
converted
that,
at 37O"C, the allene
be formed with
from
L rear5. At preA bypassing
the proposed
tures.
A / \ 9 II
/0\ 6 I
13
2 was
the proportion
affords
of 5 could
when
in an electric
of a 1:6:4 mixture
in the flow results
of ; was obtained, tube placed
to the same procedure
of l and = 5. At 420°C
it is not clear
2. The
be formed
a 40 cm Pyrex
material
into $ as the sole product.
sent
that 2 might
of J had vanished
by
of i had disappeareel. Besides
component
Therefore,
was kept
formed.
at 0.1 torr
ranges
arose
of J, but might
distilled
the expense
as the major
electrophiles.
insight
Subjecting
the signals
nitrogen,
of 1 was monitored
bicyclo[4.2.0locta-1,6-diene
suspicion
'H NMR was
in an NMR tube under
of the concentration
30 min.,
observed
rearrangement
14O"C,
ic
After
material,
As f had also been isomerization
sealed
14
struc-
5841
Unlike at 370°C. was
2, the propellane However,
isolated.
stored
to give
of the product
$j is the result
system
at 43O"C,
product.
be recognized
of the central
contrast, respect would
the concerted to orbital
diene
2. Under
versible.
Breaking
forcing
reaction
the C-6-C-7
a new C-C bond between
affording
bond
Bicyclo[4.l.O]hepta-1,5-diene 2, which diene
is formed
is an intermediate
could
In
with
undergo
a dimethyl-
11) the more
the allene
seems
from
stable to be re-
Jz and forming
6.
precursor
ring-opening
directly
6
[02s + u2al path
the diradical
(13) is the obvious _=
if 12 is produced
lead to 2.
this process
of Jp to give
can
of 1, 2 and 2.
be unfavorable
(via diradical
from 12 by an electrocyclic
.5, it is not clear,
could
favorable
VI, which
yield
framework
isomerization
conditions,
C-2 and C-6 could
in the flow (2) as the only
[l.l.l]propellane
The
intermediate
the
5
of J into 2 should
considerations.
rearrangement7 more
of the
2 isomerized
seem to suggest
of 2. Indeed,
[02s + o2a] process
conversion
be
of this reaction,
observations
of the thermal
allowed
lead to the short-lived
enecyclopropane
spectra.
C-C bond
(2)
2 showed
it could
into dimethylenecyclopropene
feature
symmetry
data.
[l.l.l]propellane
isomerization
by its NMR
symmetry
nitrogen,
(8).4 The low temperature
2 was converted
2, an orbital
that at 114°C
of a catalyzed
as a common
1,2-divinylcyclopropene
a week.
and our above-mentioned
2 was identified
Retention
For
reported
of the flow pyrolysis
on its spectroscopic
But in C6D6 under
for at least
3-methylenecyclobutene
structure
of 2 and
for 2 rests
to polymerize.
it has been
the conditions
a I:3 mixture
proof
in the refrigerator
Recently
that
at 430°C
Structure
a high propensity
1 withstood
of the triene
reaction.
As with
2 or if the diene
29
in this process.
Acknowledgement This Fonds
work
was
supported
der Chemischen
by the Deutsche
Industrie.
Forschungsgemeinschaft
and by the
5842
Table
4:
1. NMR Data
'H (C606):
'3C (C6D6):
5.80 (broad s, 1 H).
23.44,
'H (C6D6):
(4 t), 109.37,
14.15, 27.08 (2 t), 35.08
125.91 (2 d), 141.36,
148.72 (2 s).
(2 C, t), 116.73 (d), 119.28 (s).
'H (C6D6): 0.99 - 1.80 (m, 6 H), 2.06 (m, 2 H), 4.67 (m, 2 H). 13C (C6D6): 20.90
I:
23.75, 24.44, 37.01
1.05 (s, 2 H), 1.80 (m, 2 H), 2.32 (m, 4 H), 5.70 (m, 2 H).
13C (C606): G:
(6 Values)
1.38 - 1.75 (m, 2 H), 1.83 - 2.19 (m, 4 H), 2.91 - 3.14 (m, 2 H), 5.14 (t,
J = 4 Hz, 1 H),
5:
of 2 - 2 and 2
(t), 26.96
(d), 29.17
(2 C, t), 75.54 (t), 81.75,
194.79 (2 s).
’ H (C6D6): 1.18 (s, 2 H), 5.25 (dd, J = 2 Hz and J = 9 Hz, 2 H), 5.38 (dd, J = 2 Hz and J = 17 Hz, 2 H), 6.46 (dd, J = 9 Hz and J = 17 Hz, 2 H). 13C (C6D12): identified
2:
5.62,
122.60
(2 t), 125.35
(d); the signal of C-l and C-2 could not be
with certainty.
'H (Et20): 1.58 (m, 2 H), 5.27 (m, 2 H), 5.50 (m, 2 H). 13 C (Et20/CDC13): 101.38 (t), 124.80 (s); the signal of C-3 could not be identified
with
certainty.
References: Semmler,
G. Szeimies
I)
K.
2)
K. B. Wiberg, H. Huber, (1985). M.
E. Heitbronner,
K. B. Wiberg,
D. Newton,
-ibid.
J. Belzner
4)
K. B. Wiberg
5)
R. Bloch,
P. Le Perchec
Ed.
2, 798
6)
R. B. Woodward 5, 781
7)
and
J. Am.
K. Laidig,
W. P. Dailey,
7247
G. Szeimies,
and
J. Belzner, and
W. P. Dailey, IQI, -__
3)
Engl.
and
S. T. Waddell
and
Sot.
K. B. Wiberg,
F. H. Walker,
l_OZ, 6410 --_
Lett.
1986,
J. Am.
S. T. Waddell,
(1985). 1553.
Chem.
E. Honegger,
Sot.
101, _--
L. S. Cracker,
7172 and
(1985).
unpublished.
F. H. Walker, and
Chem.
Tetrahedron
J. Am.
J.-M.
Chem.
Conia,
Sot.
Angew.
Lpi, Chem.
5239 gz,
(1982). 810
(1970);
Angew.
Chem.,
Int.
(1970).
and
R. Hoffmann,
Angew.
Chem.
&
797
(1969);
Angew.
Chem.,
Int.
Ed.
Engl.
(1969).
J. J. Gajewski, Toronto,
(Received
Sydney,
"Hydrocarbon San
Thermal
Francisco,
in Germany
1981,
8 September
Isomerizations", pp 77 - 80,
1986)
and
Academic references
Press;
New
therein.
York,
London,