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The photo-fritsch-buttenberg-wiechell rearrangement
Tetrahedron Letters No. 10, pp 783 - 704, 1976.
THE
PHOTO-FRITSCH-BUTTENBERG-WIECHELL By Boris
“Joief
Stefan”
jket,
Marko
Zupan*
Ljublbna,
(Received in UK 14 The carbon,
under
Frihch-Buttenberg-Wiechell Irradiation resulted
of
We now report ethylenes/l/ 1,l -diphenyl n.m.r.,
ethylene
/3/
mass spectral
/based
on isolated
found
of 01 efins,
of
bearing
product
irradiation
irradiation
mixture
hydrogen
29
1976)
JRBUPI-y
ond halogen
with
of
on the same
/0.023
com&nds,
M/
i.e.
and 1,1,4,4-tetraphenylbutadiene The products and v.p.c.
and i.r.
in acetic
at 2537
/4/, which were-identified
data and their distribution is presented 1,l -diphenyl-2-fluoroethylene to cis-
.
A in ether
diphenylacetylene
and trans-fluorostilbene
re-
/2/,
could be by their in Table 1 has been
Furthermore,
rearrangement
ac$d
butadiene
l ,l-diphenyl-2-halogen~ubstituted
of /l/
of three
sunlight
1,1,4,4_tetrasubstituted
t.I .c.
products/.
to undergo
of
conditions has been known for a long time as the and has been studied in detail 4,516, rearrangement ‘!‘r3
A 1.5hr
by preparative
University
Liubliana
basic
the results
reaction
Pollak
accepted for publication
of the dimeric
in ether.
in a-crude
separated
and Alfred of Chemistry,
1,1-di/p-methoxyphenyl/-2-bromoethylene
in the formation
sulted
61000
1976;
Jan~01-y
dehydrohalcgenation
to acetylenes
REARRANGEMENT
Department
Institute
Printed in Great Britain,
Pergemon Press.
upon irradiation
in
ether. In order we found /5
it
and 6,‘.
action
to establish
to irradiate
Irradiation
under
mixture
of up to four
cis-stilbene
/8/
and v.p.c.
Hbwever,
conditions
the mechanism
reasonable
i.e.
products,
irradiation
/9/
conditions
resulted
diphenylacetylene
which
of cis-
to diphenylacetylene,
and cis-halogen-substituted
the above mentioned
and phenanthrene
resulted
of photorearrangement
some trans-
could
/2/,
be separated
and trans-fluorostilbenes
in photoisomerisation
and no evidence
for
stilbenes
in a crude transstilbene
by preparative under
re/7/, t .T. c.
the above
photodehydrohalogenation
was found. The
available
ethylenes followed
could
evidence
occur
via
suggests
by photodehydrohalogenation
Further
study
that
these photorearrangements
the intermediately
formed
of
halogen-substituted
l,l-diphenylstilbenes,
to diphenylacetylenes.
of the mechanism
of the new photorearrangement
is in progress.
REFERENCES: 1.
P. Fritsch,
2.
W.P.
Justus
Liebigs
Euttenberg,
3.
H.
4.
H.G.
Wiechell,
5.
G . Modena,
Viehe,
6.
G.
Kabrich,
7.
W.
Tadros,
ibid.
ibid.
279(194),
ChemisTof Accounts Angew. A.B.
Ann. 279
Sakla
Chem.,
(1894),
Chem.,
(1894),
319.
337.
Acetylenes, Chem.
279
324.
Res.,
p. 117, A (1971),
84 (19E),
and Y.3khookh,
Marcel
Dekker,
New
73.
557. J.
Chem.
Sot.,
1956,
2701.
York
1969.
No. 10
’
H
+=c @IXI
hv Et,0
b
a-czc-a)
@ J-
+
@ +
@IH
YIEL[ IS OF PRODUCTS 9%\ X 2 3
‘4
25
28
10
23
34
10
19
51
6
t
+
hv Etz 0 (0
L?
X
Q,
l-?)
H
H
H
1
s
COMPOUND
2_
1
e
9
X=CI _!i
63
16
9
-
_I!. _!i.
57 30
18 13
10 16
10
s
25
I&
19
6
x= Et
0
H
+c x
0
+
1
H
THE
PHOTO-FRITSCH-BUTTENBERG-WIECHELL By Boris
“Joief
Stefan”
jket,
Marko
Zupan*
Ljublbna,
(Received in UK 14 The carbon,
under
Frihch-Buttenberg-Wiechell Irradiation resulted
of
We now report ethylenes/l/ 1,l -diphenyl n.m.r.,
ethylene
/3/
mass spectral
/based
on isolated
found
of 01 efins,
of
bearing
product
irradiation
irradiation
mixture
hydrogen
29
1976)
JRBUPI-y
ond halogen
with
of
on the same
/0.023
com&nds,
M/
i.e.
and 1,1,4,4-tetraphenylbutadiene The products and v.p.c.
and i.r.
in acetic
at 2537
/4/, which were-identified
data and their distribution is presented 1,l -diphenyl-2-fluoroethylene to cis-
.
A in ether
diphenylacetylene
and trans-fluorostilbene
re-
/2/,
could be by their in Table 1 has been
Furthermore,
rearrangement
ac$d
butadiene
l ,l-diphenyl-2-halogen~ubstituted
of /l/
of three
sunlight
1,1,4,4_tetrasubstituted
t.I .c.
products/.
to undergo
of
conditions has been known for a long time as the and has been studied in detail 4,516, rearrangement ‘!‘r3
A 1.5hr
by preparative
University
Liubliana
basic
the results
reaction
Pollak
accepted for publication
of the dimeric
in ether.
in a-crude
separated
and Alfred of Chemistry,
1,1-di/p-methoxyphenyl/-2-bromoethylene
in the formation
sulted
61000
1976;
Jan~01-y
dehydrohalcgenation
to acetylenes
REARRANGEMENT
Department
Institute
Printed in Great Britain,
Pergemon Press.
upon irradiation
in
ether. In order we found /5
it
and 6,‘.
action
to establish
to irradiate
Irradiation
under
mixture
of up to four
cis-stilbene
/8/
and v.p.c.
Hbwever,
conditions
the mechanism
reasonable
i.e.
products,
irradiation
/9/
conditions
resulted
diphenylacetylene
which
of cis-
to diphenylacetylene,
and cis-halogen-substituted
the above mentioned
and phenanthrene
resulted
of photorearrangement
some trans-
could
/2/,
be separated
and trans-fluorostilbenes
in photoisomerisation
and no evidence
for
stilbenes
in a crude transstilbene
by preparative under
re/7/, t .T. c.
the above
photodehydrohalogenation
was found. The
available
ethylenes followed
could
evidence
occur
via
suggests
by photodehydrohalogenation
Further
study
that
these photorearrangements
the intermediately
formed
of
halogen-substituted
l,l-diphenylstilbenes,
to diphenylacetylenes.
of the mechanism
of the new photorearrangement
is in progress.
REFERENCES: 1.
P. Fritsch,
2.
W.P.
Justus
Liebigs
Euttenberg,
3.
H.
4.
H.G.
Wiechell,
5.
G . Modena,
Viehe,
6.
G.
Kabrich,
7.
W.
Tadros,
ibid.
ibid.
279(194),
ChemisTof Accounts Angew. A.B.
Ann. 279
Sakla
Chem.,
(1894),
Chem.,
(1894),
319.
337.
Acetylenes, Chem.
279
324.
Res.,
p. 117, A (1971),
84 (19E),
and Y.3khookh,
Marcel
Dekker,
New
73.
557. J.
Chem.
Sot.,
1956,
2701.
York
1969.
No. 10
’
H
+=c @IXI
hv Et,0
b
a-czc-a)
@ J-
+
@ +
@IH
YIEL[ IS OF PRODUCTS 9%\ X 2 3
‘4
25
28
10
23
34
10
19
51
6
t
+
hv Etz 0 (0
L?
X
Q,
l-?)
H
H
H
1
s
COMPOUND
2_
1
e
9
X=CI _!i
63
16
9
-
_I!. _!i.
57 30
18 13
10 16
10
s
25
I&
19
6
x= Et
0
H
+c x
0
+
1
H