HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 3, No. 5, 1975
Published online:
■ The Barrier to Ring Reversal in Some 5,5-Disubstituted 1,2,3-Trithianes
Gustaaf Goor and Marc Anteunis*
*Laboratory for NMR Spectroscopy, Department of Chemistry, State University of Gent, Krijgslaan 271 (S.4bis), B-9000 Gent, Belgium
Abstract
Barriers for ring inversion have been measured in a series of 5,5-disubstituted 1,2,3-trithianes. As expected, these derivatives inverse slower than the parent unsubstituted compound, except for 5-CH2R (R = Me, i.Pr) substituents.
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■ Synthesis of Haplamine
Pietro Venturella, Aurora Bellino, and Franco Piozzi*
*Dipartimento di Chimica Organica, Università digli Studi di Palermo, Via Archirafi 20 90123 Palermo, Italy
Abstract
The alkaloid haplamine was synthesized by isoprenylation at C-3 of 4-hydroxy-6-methoxy-2-quinolone and cyclodehydrogenation with DDQ.
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■ Conformational Analysis of Tetrahydroprotoberberines by Carbon-13 NMR Spectroscopy
Tetsuji Kametani,* Akira Ujiie, Masataka Ihara, Keiichiro Fukumoto, and Harumi Koizumi
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
The preferential conformation of tetrahydroprotoberberines is easily assignable by comparison of the chemical shift of C(6) in carbon-13 nmr spectroscopy. It is possible, furthermore, to distinguish the position of substituents in 9,10- and 10,11-substituted tetrahydroprotoberberines by the difference in chemical shift of C(8).
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■ Reactions of Pyrylium Salts with Pyridinium and Sulphonium Ylides
Alan R. Katritzky,* S. Q. Abbas Rizvi, and Jerzy W. Suwinski
*School of Chemical Sciences, University of East Anglia, Norwich, Northfolk NR4 7TJ, U.K.
Abstract
Pyrylium salts with pyridinium acylylids give 1-arylpyridinium cations by a RORC mechanism, whereas sulphonium acylylids afford furans.
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■ Pyridopyridazines. IV. Pyrido[2,3-d]pyridazine N-Oxides. A Novel Ring-Opening Reaction by Means of Acetic Anhydride
Ikutoshi Matsuura*
*Central Research Laboratories, Chugai Pharmaceutical Company, Ltd., Takada 3-41-8, Toshima-ku, Tokyo 171, Japan
Abstract
Treatment of 5-alkoxypyrido[2,3-d]pyridazines with m-chloroperbenzoic acid afforded the 7-oxides 2a and 2b, and the 1,7-dioxides 3a and 3b. 8-Alkoxypyrido[2,3-d]pyridazines however yielded the 6-oxides 2c and 2d. Of the mono-oxides 2b and 2d on treatment with acetic anhydride gave the ring-opened esters 5b and 5d and the ketoesters 6b and 6d. 1-Methoxyphthalazine-3-oxide similarly yielded benzoate 10, acetonylbenzoate 11, and methyl stilbenedicarboxylate 12.
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■ Reaction Pathway in the Photorearrangements of Phenylisothiazoles
Minoru Maeda, Akira Kawahara, Masaaki Kai, and Masaharu Kojima*
*Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Abstract
In the photorearrangement of 5-phenylisothiazole (III) in ether-deuterium oxide system, deuterium was incorporated into the product, 3-phenylisothiazole (I). It is supported that the photorearrangements of phenylisothiazoles proceed through tricyclic sulphonium cation intermediates.
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■ An Intriguing Copper Salt Effect upon the Photochemistry of Pyridine-N-oxides. Specific Photoinduced Syntheses of 3-Substituted 2-Formylpyrroles
François Bellamy, Pierre Martz, and Lacques Streith*
*Ecole Nationale Supérieure de Chimie de Mulhouse, Université du Haut-Rhin, 68093 Mulhouse, France
Abstract
Ultraviolet irradiation of pyridine-N-oxides in water leads to the isomeric 2-formylpyrroles. Copper salts, and especially copper sulfate and copper perchlorate, dramatically increase the yields of the corresponding pyrrole aldehydes.
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■ A Fascinating Synthesis of Olivacine
Tetsuji Kametani,* Yoshifumi Ichikawa, Toshio Suzuki, and Keiichiro Fukumoto
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
The tumour-inhibiting alkaloid olivacine (11) has been synthesised by a reaction of indole with 4-(1-bromoethyl)-3-bromomethyl-2-methylpyridine (10).
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■ A Novel Phthalideisoquinoline Synthesis from the Benz[d]indeno[1,2-b]azeine
Tetsuji Kametani,* Shoji Hirata, Masataka Ihara, and Keiichiro Fukumoto
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Permanganate oxidation of 12-chloro-5,6,7,7a-tetrahydro-2,3,9,10-tetramethoxy-7-methylbenz[d]indeno[l,2-b]azepine (17) in the presence of piperidine, followed by reduction with sodium borohydride gave the phthalideisoquinoline (19).
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■ Synthesis of Some N-Heterocycles Using Acetoacetamide Derivatives
Tetsuzo Kato,* Nobuya Katagiri, and Mohsen Daneshtalab
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Reaction of ethyl acetoacetate (1), ethyl β-aminocrotonate (2), acetoacetamide (3), and β-aminocrotonamide (4) with carboxylic acid derivatives, aldehydes, ketones, and diketene results in the formation of N-heterocycles. This article gives a detailed survey of the reactions of these compounds and related derivatives.