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New Observations on Acylheterocumulenes.

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and E were taken together for structural determinations. Their
reactions indicated a masked keto group (ketal). Only unbranched acids are obtained by KMnO4 degradation. Finally,
analytical data, including NMR-spectra, showed that exogonic acid is a derivative of oxetone, namely a-methyl-dcarboxymethlloxctone (2), a diketal with an unbranched
carbon chain.
E. Broclimnnn-Hcitissen, San Francisco, Calif. (U.S.A.), succeeded in isolating a new phenolic base from opium alkaloids
and elucidating its structure. This base is apparently of great
importance in the biosynthesis of the other alkaloids. Firstly,
the alkaloid extract was adjusted to pH 1 and was then extracted with CHCI3. The aqueous epiphase was mixed with
dichloroacetic acid and again shaken with chloroform. The
extract is then evaporated to dryness, and the residue subsequently dissolved in dilute sodium hydroxide and treated
once more with chloroform. Only phenolic substances, including the new alkaloid, termed reticuline, remain in the
aqueous phase. Reticulinc can be converted into ('blaudanosine with diazomethane, thus establishing its basic structure.
The substance possesses two methoxy groups and two phenolic hydroxy groups. Comparison of its NMR-spectrum with
those of some synthetically available partial methyl ethers
with laudanosine structure made it possible to establish the
position of the substituents, resulting in structure (3). The
compound is probably an intermediate in the biogenesis of
the other opium alkaloids:
New Observations on Acylheterocumulenes
J. Goerdeler, Bonn (Germany)
Acyl isothiocyanates ( I ) add onto C-2 of I-alkoxy-l-aminoor I , 1-diaminovinyl ketones (2) or analogously substituted
acrylic esters (2) [l] to form compounds (3). Cyclization of
(3) can be induced by alkali or occurs spontaneously and
yields 4-mercaptopyrimidines (4) with amino or alkoxy
groups in the 6-position. Alternatively, dehydrogenative
cyclization leads to 3,5-diaminoisothiazoles (5) or 3-alkoxy-5aminoisothiazoles ( 5 ) (experiments with U . Keuser).
i;'
(2) I-12N-C=CH-122
i i ~R ~ - C O - N C S
-
H 2 N - C =y - R 2
f3)
s=c- €41I- Colt3
f4 )
( 51
R1 = OR, S H z ; K 2 = COK, COOR
Monomeric N-substituted a-iminoalkyl isothiocyanates (6)
are readily converted into dimers (cc-iminoalkyltriazinedithiones) [2]. On the other hand, they are easily cyclized to
1,3,5-triazine-2,4-dithiones
(7) by thiocyanic acid. This confirms the hypothesis of I. Ugi and F. Rosendalil [3] that an M iminoalkyl isothiocyanate is formed as an intermediate when
laudanine - codanine - laudanosine
protopine
H,CO
1 ' ,
reticuline
J
thebaine
*'
-
ldudanidine
codeine - morphine.
H~T
-CH3
13)
Y O .
OCH,
According to T. Harrmann, Bonn (Germany), the biogenesis
of volatile amines can be formally represented as the decarboxylation of the corresponding amino acids. Additions of
leucine to mycelial cultures of Clnviceps purpureci do indeed
lead to the formation of isoamylamine. However, until now,
no amino acid was known which could be responsible for the
abundant occurrence therein of n-hexylamine. Accurate analyses of the mycelia, which accumulate n-hexylamine, have
now demonstrated the presence of an amino acid which is
chromatographically identical with synthetic u-aminoheptanoic acid. The acid is readily identifiable in young myceha.
Its presence could not be demonstrated in Secnle cornutum,
however. It was not possible to show that other volatile amines
arose by direct decarboxylation of amino acids. This concept
should not, therefore, be generalized. For identification, the
amines were treated with dinitrofluorobenzene and separated
by partition chromatography on paper impregnated with
paraffin oil using methanol/water (10:6) as eluant.
R . Tsclierclre, Bonn (Germany), spoke on the constitution of
saponins, their hemolytic activity, and their ability to form
complexes with sterols. An elegant method was elaborated
for examining their complexing ability. The saponin is transferred to a paper strip, together with 14C-labeIled cholesterol,
and the paper developed with carbon tetrachloride. If a complex has been formed, the total radioactivity, o r at least most
of it, remains with the saponin at the start. If complex formation does not occur, however, the cholesterol is eluted by
the carbon tetrachloride. In this way it was possible to determine whether there is a connection between hemolytic index
and complex formation. This seems to be the case to only a
very limited extent. Rather, the hemolytic index seems to
depend in equal proportions on complex formation, detergent
character, and protein association.
[VB 826/152 IE]
German version: Angew. Chem. 76, 723 (1964)
594
S
HSCN adds onto an isonitrile. It should be mentioned, however, that methyl and phenyl isothiocyanates do not add onto
monomeric a-iminoalkyl isothiocyanates.
Thermal decomposition of 2-arylthiazoline-4,5-diones yields
arylthioacyl isocyanates (8) [4] ; phenylthioacyl isocyanate
was isolated as red crystals, m.p. 16.5 "C. Additions of arcmatic and heterocyclic amines onto ( 8 ) yield thioacylated
ureas; in the aliphatic series, side reactions occur. Thiobenzoylurea can, however, be readily obtained by hydrolysis
of N-thiobenzoy-IN'-benzoylurea.
I ,4-Cycloadditions onto (8) with morpholinohexene, N,N'dicyclohexylcarbodiimide, N-benzylideneaniline, and phenyl
isocyanate afford thiazine or thiadiazine derivatives (9) ; the
corresponding reaction with isonitriles affords 2-aryl-4-0x05-alkyliminothiazolines (10). Benzoyl isocyanate reacts in
an analogous manner [ 5 ] . These cycloadditions are reversible
and can be carried out in most cases with the precursors of
the thioacyl isocyanates (experiments with H. Schenk).
[GDCh-Ortsverband Krefeld, Krefeld-Uerdingen (Germany),
April 30th, 19641
[VB 821/150 IE]
German version: Angew. Chem. 76, 654 (1964)
.I. Goerdeler and H . Polilnrd, Chem. Ber. 96, 526 (1963).
J. Goerdeler and D . Weber, Tetrahedron Letters 1964, 799.
I. r/ni and F. Ro.~enilahl,Liebigs .Ann. Chem. 670, 80 (1963).
J. Goerdeler and H. Scherrk, Angew. Chem. 75, 675 (1963);
Angew. Chem. internat. Edit. 2, 552 (1963).
[5] R. Neid/ein has independently observed the same isonitrile
reaction with benzoyl and thiobenzoyl isocyanates [Angew.
Chem. 76, 596 (1964)l.
[I]
[2]
[3]
[4]
Angew. Chem. internat. Edit.
/ Vol. 3 (1964) / No. 8
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acylheterocumulenes, observations, new
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