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. 8, 1975
Published online:
■ Indolizine Derivatives. IV. Evidence for a Disproportnation Dehydrogenation Mechanism in the Perkin Reaction of 2-Pyridinecarbaldehyde in the Presence of α,β-Unsaturated Carbonyl Compounds to Give 1-Acylpyrrolo[2,1,5-cd]indolizines
Esko Pohjala*
*Department of Chemistry, Technical University of Helsinki, P.O. Box 6100, FIN-02150 HUT Espoo, Finland
Abstract
In the Perkin reaction of 2-pyridinecarbaldehyde (1) with 3-buten-2-one (2) and Ac2O/KOAc the normal Perkin reaction product, acetic 3-(2-pyridyl)acrylic anhydride (3), disproportionates. The reduction products include 3-indolizinyl acetate (4), which with 2 cyclizes to 1-(1,2-dihydro-1-pyrrolo[2,1,5-cd]ndolizinyl)ethanone (5). Dehydrogenation of 5 then affords 1-(1-pyrrolo[2,1,5-cd]indolizinyl)ethanone (6).
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■ Novel Formation of the Benzimidazo[2,1-a]isoquinoline and Benz[c]acridine from the 1,2,3,4-Tetrahydro-1-(2-nitrophenethyl)-isoquinoline with Triethyl Phosphite
Tetsuji Kametani,* Yasuo Fujimoto, and Masakatsu Mizushima
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Reductive cyclisation of 1,2,3,4-tetrahydro-6,7-dimethoxy-1-(4,5-dimethoxy-2-nitrophenethyl)isoquinoline (10) and its 2-methyl derivative (11) with triethyl phosphite gave 5,6-dihydro-2,3,9,10-tetramethoxybenzimidazo[2,1-a]isoquinoline (13) and 2,3,9,10- tetramethoxybenz[c]acridine (18), respectively.
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■ A Total Synthesis of Angustine
Tetsuji Kametani,* Mitsuhiro Takeshita, Masataka Ihara, and Keiichiro Fukumoto
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
A total synthesis of angustine (1) was accomplished via condensation of tryptamine with the lactone (5) which was prepared from 4-methyl-5-vinylnicotinonitrile (4), followed by cyclisation of the 7-azacarbostyril (8). Gentianine (6) was also synthesised by two routes from the nicotinonitrile (4).
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■ Reaction of m-Nitrobenzylideneacetylacetone with Phenyl- and Methylhydrazines
Takushi Kurihara,* Toshiko Sakaguchi, and Hiroshi Hirano
*Faculty of Pharmaceutical Science, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan
Abstract
Reaction of m-nitrobenzylideneacetylacetone with phenyl- and methylhydrazine in aqueous acetonitrile, methanol, and glacial acetic acid afforded 4-(α-hydroxy-, methoxy-, and acetoxy-m-nitrobenzyl)-3,5-dimethyl-1-phenylpyrazoles (Va-VIIa) and the corresponding 1-methyl derivatives (Vb-VIIb), presumably via the pseudo-bases (III), in excellent yields.
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■ Studies on the Synthesis of Bisindole Alkaloids. II. The Synthesis of 3’,4’-Dehydrovinblastine, 4’-Deoxovinblastine and Related Analogues. The Biogenetic Approach
James P. Kutney,* Arnold H. Ratcliffe, Adi M. Treasurywala, and Stephen Wunderly
*Department of Chemisry, University of British Columbia, Vancouver 8, V5T 1W5, Canada
Abstract
A novel approach to the synthesis of bisindole alkaloids in the vinblastine series has been developed. This approach, which originates from biogenetic considerations is exemplified by the coupling of catharanthine and dihydrocatharanthine N-oxides with vindoline under Polonovski-type fragmentation conditions. The method which provides dimers with natural stereochemistry at C18, represents an exciting entry into this complex family from two readily available alkaloids.
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■ Furazans
Kenneth L. Stuart*
*Department of Chemsitry, University of the West Indies, Mona, Kingston 7, Jamaica
Abstract
The Chemistry and uses of furazans (1,2,5-oxadiazoles) and furoxans (furazan-2-oxides) are reviewed.