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A contribution to the structure of valeranone
TetrahedronLetters No. 5, pp. 169-173, 1962. Pergamon Press Ltd. Printed in Great Britain.
A CONTRIBUTIONTO THE STRUCTURE OF VALERANONE J. Kfepinskq,M. Roma%k, V. Herout and F. Sorm Institute of Organic Chemistry and Biochemistry CzechoslovakAcademy of Science, Prague (Received22 January 1962; in revised form 26 February 1962)
IN a previous communication,'we proposed two alternativeformulaeI and II for valeranone. Shortly afterwards,structureIII was ascribed to valeranone & by GovindachariA, et al -2,3 the authors used, incorrectlyin our opinion,
(2%cp” I
@
0 Ill
FIG. 1
w IV
the term jatamansoneinstead of the name valeranone. The configurationof
.
5 who suggested methyl group on C(lo) was studied by Djerassi and co-workers 1 2
J. Kr*epinsky', M. Romaiiuk,V. Herout and F. Sorm, TetrahedronLetters No. 7, 9 (1960). T.R. Govindachari,B.R. Pai, K.K. Purushothamanand S. Rajadurai,Chem. & && 1059 (1960).
3 T.R. Govindachari,BR. Pai, K.K. Purushothamanand S. Rajadurai, ’ Tetrahedron&, 105 (1961). 4 J. K?epinskq,V. Herout and F. sorm, TetrahedronLetters No. 3, 9 (1960). 5 C. Djerassi, T.R. Govindachari,B.R. Pai and TetrahedronLetters No. 6, 226 (1961). 169
K.K.
Purushothaman,
170
A contributionto the structureof valeranone
No.5
structureIV for valeranoneon the basis of rotatory dispersionarguments which assumed that II representedthe correct skeletal structure. The main sequence of r,aactions which led Govindachariet al. to structureIII is outlined in Scheme 1 (V-VII);on treatmentwith dimethyl aniline the substance V was dehydroorominatedto a,p-unsaturatedanhydrideVI and this on Lemieux 6 and Rudloff oxidation afforded,accordingto the work of Govindachari et al.3 , l-tgJns-carvomentone.In our preliminarynote' we reported already that on treatmentof substanceV with collidineor dimethyl aniline, no product of normal dehydrobromination could be obtained. As the absorption
bands of the dehydrobrbmination product obtained both by the Indian authors3 (1786, 1672, 1695 cm-') and in this Laboratoryas well (1782, 1682, 1496, 1598, 3062 cm-') had been at variance with the formula VI, we re-investigated the reaction in a greater detail. We ascertainedthat besides trimethyl phenylammoniumbromide VIII, a substanceof molecular formula C
2o + 2oo". H 0 N (IX) was formed, m.p. 144' (diisopropylether), LoI, 21 29 3 The absorptionbands of IX in the infra-redregion showed the presence of an aromatic system (1496, 1598, 3062 em-'), a lactone (1782 cm-') and an amide group (1682 cm-'). We have explainedthe unexpected formationof IX by a rearrangement,*the course of which may be seen in Scheme 2.
+ 6
The rearrangementis studied in detail'at present. R.V.
Lemieux and E. v. Rudloff,Canad. J. Chem. 2,
1701, 1710 (1955).
No.5
A contribution
As the physical resembled, might
we anticipated
be identical;
melted
data
this
undepressed
&QfJ% N).
*
by the
of
Indian
Nevertheless,
the structure
both
the
proved
in all authors
that
to be true of
IX.
respects
Our thanks are due to Professor Madras, India, who kindly sent
both
171
compounds
when an authentic
The infra-red as well;
contained
we attempted
of valeranone
compounds VI and IX strikingly
the possibility
on admixture
and IX were identical prepared
to
to carry
out the
sample
spectra
in addition,
3.81% nitrogen
in question
(for
of the
of VI*
both
VI
sample
IX calculated
oxidation
T.R. Govindachari, Presidency us a sample for comparison.
of
IX by
College,
A contribution
172
means
of Lemieux
should
result
only
in
starting above the
cable,
for
yielded
zation,
the
for
between
we used
following
perbenzoic
acid,
based
compound
ester
with
nation
with
yielded
collidine
234 rnp (log
C15H24039 ‘max monocyclic
compounds,
good
agreement
(methyl
ester)
in
agreement
good
corresponds there
is
to
with
only
of
II
these
The other
main
features
structure
XIII.
*
Woodward,
due the
cm-l
ester
would in
an
have the
(carbonyl compound
C=CH
atom
in
Chem.
the
and
given
separate
spectrum
are
the
Sot.
value
bands
at
1123
in
more
(1941).
the
values
for
(235
mp) and
(234 1744,
the
mp) was 1429
cm
-1
conclusion
band
at
T=
shows
is 4.2 that
The corresponding
peaks
University NMR spectrum
ozoni-
XIII,
intensity
hydrogen
also
and
This the
its
a,a-unsaturated
@,
diazo-
dehydrobromi-
our
molecule.
two ethylenic
to Dr. N. Sheppard, measurement of the Amer.
group
with
XII;
with
XIII:
on 61-62’
ester
group).
3):
X, m.p.
treatment
methyl
that
appli-
by us
Scheme
subsequent
keto
infra-red
of
now not
suggested (cf.
(By comparison
XII17)
contains
On ozonization,
J.
II
methyl and
mp) we found
1634
from
that
7 R.B.
s = 4.131)5
valeranone,
On dehydration
keto
a,p-unsaturated
hydrogen
feel
are for
desmethyl
results for
s-lactone
XI.
however,
I.
subsequent
N-bromo-succinimide
such
derived
Our thanks Cambridge,
and
the
III
reactions
afforded
authors,
hands,
of
than I and
of
Indian
IV are
rather
of hydroxy-acid
NMR spectrum
hydrogen
structure sure
1672,
with
one
light
structure
structures
valeranone
structure
at
the
II
the
our
configuration
sequence
(226
and
the
No.5
3-methyl-6-isopropylcyclohex-2-enone
4-isopropylcyclohex-2-enone in
both
XI afforded
on brolnination
to in
well-founded
hydrolysis
latter
according
In
on skeleton
on alkaline methyl
which,
absolute
decide
which
methane
consider
to
with
6
of valeranone
be recovered.
were
valeranone,
(pentane),
could
adduced
structure
1-m-carvomentone;
they
order
treatment
of
we cannot
the
method
formation
arguments
since In
Rudloff
material
discussed while
and
to
atoms the
4 to
and
5 region.
consistent
with
keto
XIII
ester
we
Chemical Laboratory, and valuable discussion.
No.5
A contribution
afforded ment
an ester
with
1748
cm-1
- methyl
the
ultra-violet
1.540;
the
sample
tricarboxylic
calculated
keto
diazomethane
chain;
For
of
29.43%
to
structure
dicarboxylic
yielded ester,
keto
and
at
spectrum contained ester
the
dimethyl
1725
cm
showed
22.46
assumed
acid
-1
of
XIV,
which
ester - keto
absorption
- CXH3, calculated from
the
alternative
173
valeranone
on subsequent
XV (infra-red group
treat-
bands
on an aliphatic
band
at for
280 mp XC 21.66%
structure
II
log
c =
- CCH3. was
- GCH3).
Professor Govindachari has informed us that he has re-investigated the compound called dehydronorjatamansic anhydride and its oxidation with periodate, after perusing this paper sent to him in advance of publication. He has concluded that the view expressed by him about the nature of this compound was incorrect and that the claim made in his paper to have oxidized this compound to 1-a-carvomenthone was erroneous.
A CONTRIBUTIONTO THE STRUCTURE OF VALERANONE J. Kfepinskq,M. Roma%k, V. Herout and F. Sorm Institute of Organic Chemistry and Biochemistry CzechoslovakAcademy of Science, Prague (Received22 January 1962; in revised form 26 February 1962)
IN a previous communication,'we proposed two alternativeformulaeI and II for valeranone. Shortly afterwards,structureIII was ascribed to valeranone & by GovindachariA, et al -2,3 the authors used, incorrectlyin our opinion,
(2%cp” I
@
0 Ill
FIG. 1
w IV
the term jatamansoneinstead of the name valeranone. The configurationof
.
5 who suggested methyl group on C(lo) was studied by Djerassi and co-workers 1 2
J. Kr*epinsky', M. Romaiiuk,V. Herout and F. Sorm, TetrahedronLetters No. 7, 9 (1960). T.R. Govindachari,B.R. Pai, K.K. Purushothamanand S. Rajadurai,Chem. & && 1059 (1960).
3 T.R. Govindachari,BR. Pai, K.K. Purushothamanand S. Rajadurai, ’ Tetrahedron&, 105 (1961). 4 J. K?epinskq,V. Herout and F. sorm, TetrahedronLetters No. 3, 9 (1960). 5 C. Djerassi, T.R. Govindachari,B.R. Pai and TetrahedronLetters No. 6, 226 (1961). 169
K.K.
Purushothaman,
170
A contributionto the structureof valeranone
No.5
structureIV for valeranoneon the basis of rotatory dispersionarguments which assumed that II representedthe correct skeletal structure. The main sequence of r,aactions which led Govindachariet al. to structureIII is outlined in Scheme 1 (V-VII);on treatmentwith dimethyl aniline the substance V was dehydroorominatedto a,p-unsaturatedanhydrideVI and this on Lemieux 6 and Rudloff oxidation afforded,accordingto the work of Govindachari et al.3 , l-tgJns-carvomentone.In our preliminarynote' we reported already that on treatmentof substanceV with collidineor dimethyl aniline, no product of normal dehydrobromination could be obtained. As the absorption
bands of the dehydrobrbmination product obtained both by the Indian authors3 (1786, 1672, 1695 cm-') and in this Laboratoryas well (1782, 1682, 1496, 1598, 3062 cm-') had been at variance with the formula VI, we re-investigated the reaction in a greater detail. We ascertainedthat besides trimethyl phenylammoniumbromide VIII, a substanceof molecular formula C
2o + 2oo". H 0 N (IX) was formed, m.p. 144' (diisopropylether), LoI, 21 29 3 The absorptionbands of IX in the infra-redregion showed the presence of an aromatic system (1496, 1598, 3062 em-'), a lactone (1782 cm-') and an amide group (1682 cm-'). We have explainedthe unexpected formationof IX by a rearrangement,*the course of which may be seen in Scheme 2.
+ 6
The rearrangementis studied in detail'at present. R.V.
Lemieux and E. v. Rudloff,Canad. J. Chem. 2,
1701, 1710 (1955).
No.5
A contribution
As the physical resembled, might
we anticipated
be identical;
melted
data
this
undepressed
&QfJ% N).
*
by the
of
Indian
Nevertheless,
the structure
both
the
proved
in all authors
that
to be true of
IX.
respects
Our thanks are due to Professor Madras, India, who kindly sent
both
171
compounds
when an authentic
The infra-red as well;
contained
we attempted
of valeranone
compounds VI and IX strikingly
the possibility
on admixture
and IX were identical prepared
to
to carry
out the
sample
spectra
in addition,
3.81% nitrogen
in question
(for
of the
of VI*
both
VI
sample
IX calculated
oxidation
T.R. Govindachari, Presidency us a sample for comparison.
of
IX by
College,
A contribution
172
means
of Lemieux
should
result
only
in
starting above the
cable,
for
yielded
zation,
the
for
between
we used
following
perbenzoic
acid,
based
compound
ester
with
nation
with
yielded
collidine
234 rnp (log
C15H24039 ‘max monocyclic
compounds,
good
agreement
(methyl
ester)
in
agreement
good
corresponds there
is
to
with
only
of
II
these
The other
main
features
structure
XIII.
*
Woodward,
due the
cm-l
ester
would in
an
have the
(carbonyl compound
C=CH
atom
in
Chem.
the
and
given
separate
spectrum
are
the
Sot.
value
bands
at
1123
in
more
(1941).
the
values
for
(235
mp) and
(234 1744,
the
mp) was 1429
cm
-1
conclusion
band
at
T=
shows
is 4.2 that
The corresponding
peaks
University NMR spectrum
ozoni-
XIII,
intensity
hydrogen
also
and
This the
its
a,a-unsaturated
@,
diazo-
dehydrobromi-
our
molecule.
two ethylenic
to Dr. N. Sheppard, measurement of the Amer.
group
with
XII;
with
XIII:
on 61-62’
ester
group).
3):
X, m.p.
treatment
methyl
that
appli-
by us
Scheme
subsequent
keto
infra-red
of
now not
suggested (cf.
(By comparison
XII17)
contains
On ozonization,
J.
II
methyl and
mp) we found
1634
from
that
7 R.B.
s = 4.131)5
valeranone,
On dehydration
keto
a,p-unsaturated
hydrogen
feel
are for
desmethyl
results for
s-lactone
XI.
however,
I.
subsequent
N-bromo-succinimide
such
derived
Our thanks Cambridge,
and
the
III
reactions
afforded
authors,
hands,
of
than I and
of
Indian
IV are
rather
of hydroxy-acid
NMR spectrum
hydrogen
structure sure
1672,
with
one
light
structure
structures
valeranone
structure
at
the
II
the
our
configuration
sequence
(226
and
the
No.5
3-methyl-6-isopropylcyclohex-2-enone
4-isopropylcyclohex-2-enone in
both
XI afforded
on brolnination
to in
well-founded
hydrolysis
latter
according
In
on skeleton
on alkaline methyl
which,
absolute
decide
which
methane
consider
to
with
6
of valeranone
be recovered.
were
valeranone,
(pentane),
could
adduced
structure
1-m-carvomentone;
they
order
treatment
of
we cannot
the
method
formation
arguments
since In
Rudloff
material
discussed while
and
to
atoms the
4 to
and
5 region.
consistent
with
keto
XIII
ester
we
Chemical Laboratory, and valuable discussion.
No.5
A contribution
afforded ment
an ester
with
1748
cm-1
- methyl
the
ultra-violet
1.540;
the
sample
tricarboxylic
calculated
keto
diazomethane
chain;
For
of
29.43%
to
structure
dicarboxylic
yielded ester,
keto
and
at
spectrum contained ester
the
dimethyl
1725
cm
showed
22.46
assumed
acid
-1
of
XIV,
which
ester - keto
absorption
- CXH3, calculated from
the
alternative
173
valeranone
on subsequent
XV (infra-red group
treat-
bands
on an aliphatic
band
at for
280 mp XC 21.66%
structure
II
log
c =
- CCH3. was
- GCH3).
Professor Govindachari has informed us that he has re-investigated the compound called dehydronorjatamansic anhydride and its oxidation with periodate, after perusing this paper sent to him in advance of publication. He has concluded that the view expressed by him about the nature of this compound was incorrect and that the claim made in his paper to have oxidized this compound to 1-a-carvomenthone was erroneous.