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a-Pyran and -Thiopyran.

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be reacted with phosphoric acid, azodiisobutyric acid
nitrile, and K 2 S 2 O 8 to give polymers of various consistencies. Moreover, copolymerizations with methyl
methacrylate, styrene, chloroprene and formaldehyde
1261 have also proved successful. Further copolymeriza-
tions have been carried out between cinnamoylferrocene
and styrene, acrylonitrile, methyl methacrylate, ethyl
acrylate, 1,1'-dihydroperfluorobutylacrylate, butadiene
and isoprene [137], as well as between tricarbonyl(cinnamoylcyclopentadieny1)manganese and styrene [1241.
[I371 L. E. Coleman and M . D . Rausch, J. Polymer Sci. 28, 207
(1958).
I1381 E. 0. Fischer, K. ofere et al., Chem. Ber. 91, 2763 (1958).
[139] B. Nicholls and M . C . Whiting, J. chem. SOC.(London) 551
Sincere thanks are due to my teacher, Prof. Dr. E. 0 . Fischer, for his interest in this work and for valuable discussions and suggestions.
Received, August 22nd. 1961
(1959).
[A 182/23 IE]
COMMUNICATIONS
y-Pyran and y-Thiopyran
By Dr. J. Strating, cand. &em. J. H. Keijer,
cand. chem. E. Molenaar, and Dr. L. Brandsma
4-(Dimethylallyl)tryptophan, a Precursor
of Clavine Alkaloids
By Prof. Dr. H. Plieninger, Dr. R. Fischer,
and Dipl.-Chem. V. Liede [*I
Organic Chemistry Department,
University of Groningen (Holland)
Organisch-Chemisches Institut
der Universitat Heidelberg (Germany)
The hitherto unknown parent heterocyclic systems y-pyran
(I) and y-thiopyran (11) can be synthesised from glutardialdehyde by application of Brandsma and Arens' method [l].
CHzCIz
/CH2-cHo
HzC,
CHI-CHO
--
+ 2 H C l ; -HCI + /-\x
CHZCli
L{
4
+ HzS + 2 HCI; -HzO
/Tx
t
\=/
(I):
(11):
CI
J
CsHsN(CzHs)z
-2 HCI
x= 0
x= s
y-Pyran (I) was obtained as a 90% pure product by vacuum
distillation (40-15 mm. Hg) of the reaction mixture at 9 "C
(59 g. from 100 g. glutardialdehyde). Purification by fractional distillation at normal pressure gave 15 g. of pure
colourless y-pyran (b.p. 80°C/760 mm., n g = 1.4559). The
product quickly turns brown in contact with air. The 2,4dinitrophenylhydrazone derivative of glutardialdehyde forms
rapidly on addition of 2,4-dinitrophenylhydrazinein ethanol/
H2SO4. The ultraviolet absorption spectrum of the pure ypyran in methanol showed peaks at 222 mp (E = 7035) and
238 mp (E = 5125); infrared bands lie at 3170~m-1(C-H),
1700 cm-l(C=C) [2], 1660 cm-t(C=C),and 1280-1260cm-~
(C-0-C).
In the living cell clavine and ergot alkaloids are synthetised
from tryptophan and 3,5-dihydroxy-3-methylvalericacid
(mevalonic acid) or isopentenyl pyrophosphate [l]. We wished
to ascertain whether the isoprenoid residue condenses with
the tryptophan in the 4-positisn to give 4-(dimethyallyl)tryptophan (I), or whether it first combines with the alanine
side-chain of the tryptophan.
Using radio-active formaldehyde, we obtained p-14C labelled
4-(dimethylallyl)tryptophan with a specific activity of 89
pC/mmole ;the synthesis of 4-(dimethylallyl)tryptophanstarting from 4-bromoindole-2-carboxylic acid will be published
elsewhere. The tryptophan derivative (100 mg) was added
to a 10-day old saprophytic culture of the ergot fungus of
African millet (Pennixrum typhoideum Rich.) [2] in 250 ml.
nutrient medium. After working-up [3], the crude alkaloid
mixture showed a very high activity. Elymoclavine (200 mg)
was added to the mixture and the total elmyoclavine present
recrystallised to constant specific activity (0.64 yC/mmole).
Allowing for the elymoclavine yields normally obtained
(400 mg per litre culture filtrate) and the additional inactive
elymoclavine, the incorporation rate is at least 5 %.
An amine, which after acetylation can no longer be extracted
with 2 N HCI, is present among the crude radio-active
alkaloids. This compound is either 4-(dimethylallyl)tryptamine or chanoclavine.
This work shows that the clavine alkaloids, and therefore
probably all ergot alkaloids, are formed according to the
following reaction scheme :
Crude y-thiopyran distilled on heating the reaction mixture
to 120°C (60-15 mm. Hg). A 20 % over-all yield of the pure
substance (11; b.p. 30 'C/12 mm., n g = 1.5623) was obtained
by fractional distillation in vacuo. The compound darkens
rapidly in the air at room temperature, but is much more
stable in the solid state (m.p. -28 "C). Reaction of (11) with
2,4-dinitrophenylhydrazine reagent (as above) takes place
much more slowly than in the case of (I) but yields the same
product; H2S is evolved. The ultraviolet spectrum of the
pure y-thiopyran in petroleum ether has a peak at 278 mp
(E = 2430) and a shoulder at 236-238 mp ( E = 5265); the
infrared spectrum shows characteristic bands at 3 100 cm-1
(C-H), 1640 and 1600 cm-1 (C=C) and 750 cm-1 (C-S).
Received, March 26th. 1962
[Z 272/10l IE]
[I 1 L. Brandsma and J. F. Arens, Recueil Trav. chirn. Pays-Bas 81.
33 (1961).
[21 R. Gompper and 0.Christman, Chem. Ber. 94, 1784 (1 961).
Angew. Chem. internat. Edit. I Vol. I (1962) / No. 7
Elymoclavine
Chanoclavine
399
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