close

Вход

Забыли?

вход по аккаунту

?

New Results in the Chemistry of Quasi-Aromatic Compounds.

код для вставкиСкачать
from acetate residues exclusively, it may be considered that
the CI unit (formaldehyde equivalent) in indole alkaloids of
the a-type is located in ring E and not in ring D [corresponding to a bridge between the CH,-groups of ( 2 ) or
( 3 ) ] . Preliminary tracer experiments seem not to preclude
this possibility [3].
A vinylogue of I-methyl-4-cyclopentadienylidene-l,4-dihydropyridine with n = 3 was obtained similarly. It is a
strongly basic, labile, blue compound.
1,2,6-Trimethyl-4-cyclopentadienylidene(or -4-indenylidene-)
1,4-dihydropyridine is a particularly good model for studying
electrophilic substitutions in quasi-aromatic systems. The
indenylidene compound (3) undergoes reactions at the 3'position: protonation gives (.?a), nitrosation yields (3b),
benzoylation leads to (3c), coupling with aromatic diazonium salts gives (Jd), and on substitution with dimethylformamide/phosphorus oxychloride one obtains (3e) ; substitution with azastreptocyanin cations also occurs at the
3'-position.
During attempts to convert acylalkenylamines of type (4)
and (5) [R = H or alkyl, R' = alkyl or aryl] into their hydrochlorides, they cyclized in a Pictet-Spengler-type reaction to
yield derivatives of tetrahydroisoquinoline or tetrahydro-3carboline with one o r two substituents in the I-position.
These compounds can in turn be converted into heterocycles
of the type (1)-(3) [ D . Lnudieii, Th. Rnnbe]. Dihydroresorcinol condenses with tryptamine hydrochloride to give a n
acylalkenylamine analogous to (5). Tryptaminobutenone
(5), R = H, R = CH3, reacts with acids t o form the pyridiniuni salt (6).
[GDCh-Ortsverband Muhlheini/Ruhr (Germany),
November 1 Ith, 19641
[ V B 8861195 I € ]
0
H,d
(31
0
Ch. Jurz, Munchen (Germany)
3,4-Bis-(9'-fluorenylidenemethyl)-6-(9'-fluorenyl)fulvene was
prepared as red needles, m. p. 234.5 OC, via its anion ( I ) ,
Amax = 588 mp, log E = 4.87, from 3,4-bis-(9'-fluorenylideneprethyl)-6-dimethylaminofulvene and fluorenyl-lithium. It
moved to be the most acidic hydrocarbon known to date. In
the anion ( I ) , the negative charge can be distributed over
four cyclic 5;-sextets.
(3d
.1
German version: Angew. Chern. 77, 224 (1965)
New Results in the Chemistry of
Quasi-Aromatic Compounds
4- p y r idinyl
(34
(3b): Y = NOH
8
(3cj: Y
=
C(OH)-C+jHs
(3e): Y = CH-N(CH&z
Cyclopentadienylsodium or indenylsodium displace the
secondary amino group in salts of type (3e) to form intensely
colored merocyanins with a latent carbanionomethine
structure (4).
[GDCh-Ortsverband Dusseldorf (Germany),
December 7th, 19641
[VB 8871196 IE]
German version: Angew. Chern. 77, 224 (1965)
P
Syntheses of Heterocyclic 0- and N-Glycosides
W. Pfleiderer, Stuttgart (Germany)
Related to the 9-aminofulvenes are the deep-colored heterologues of sesquifulvapolyene. Vinylogous l-methyl-4(2)fluorenylidene-l,4(1,2)-dihydroquinolines, e.g. (Z),
were
made by treating the corresponding polymethine salts with
fluorene and sodium methoxide. Protonation of the 9position of the fluorenyt residue with mineral acids gives rise
to quinolinium salts.
2-Amino-4-alkoxy-7-oxodihydropteridines
are converted, on
direct glycosidation under the conditions described by Fischer and Helferich, into 2-amino-4-alkoxy-7-glycosyloxypteridines [ I ] . Pteridine N(S)-glycosides were not obtained,
even after varying the substituent on the pyrimidine moiety
of the 7-hydroxypteridine skeleton. 4-Dimethylamino- ( l a )
[ 2 ] , 2-amino- ( I b ) , and 2-dimethylamino-7-oxodihydropteridine ( l c ) in the form of their heavy-metal salts react
uniformly with a-acetobromoglucose to yield the 0-glycosides
(2a) -(2c).
R'
H3C -
Acetobromoglucose
A g or H g salt
f 2)
n = 0, 1, 2, 3
Xylene
*.
H
*
fI)
R' = (CH,),N; R2 = H
131 Cf. the contradictory results obtained by E. Leete and S. Ghosal, Tetrahedron Letters 1962, 1179, and by A . R . Battersby,
R . Binks, W . Lawrie, G . V . Parry, and B. R . Webster, Proc. chem.
(2)
Soc. (London) 1963,369.
Angew. Chem. internat. Edit. 1 Vol. 4(1965)
R' = H; R2 = NH2
R' = H; R' = (cH,),N
1 No. 3
OAc
26 1
Документ
Категория
Без категории
Просмотров
0
Размер файла
105 Кб
Теги
chemistry, compounds, results, quasi, aromatic, new
1/--страниц
Пожаловаться на содержимое документа