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. 4, No. 2, 1976
Published online:
■ The Reaction of 2-Chloro-1-azaazulenes with Grignard Reagents
Noritaka Abe*
*Department of Chemistry, Faculty of Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8512, Japan
Abstract
Reaction of 2-chloro-1-azaazulenes with phenylmagnesium bromide gave addition-type products, and dehydrogenation thereof afforded 4-, 6-, and 8-phenyl-2-chloro-1-azaazulenes. It is concluded from product yields that the reactivity of the ring position of the 2-chloro-l- azaazulene system towards this reagent increases in the order of C(8)»C(4)>C(6).
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■ Bisindoxyl-derived Blue Marine Pigments
Tatsuo Higa and Paul J. Scheuer*
*Department of Chemistry, University of Hawaii at Manoa, 2545 Tha Mall, Honolulu,
Hawaii 96822-2275, U.S.A.
Abstract
From the marine invertebrate Ptychodera flava laysanica we have isolated three blue pigments, the known 6,6’-dibromoindigotin (I) as well as the previously unreported 5,7,5’,7’-tetrabromo-6,6’-dimethoxyindigotin (III) and 5,7,6’-tribromo-6-methoxyindigotin (IV) in addition to a colorless companion, 5,7-dibromo-6-methoxyindole (V).
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■ Synthesis and Properties of 6-Bromo-3-chloro- and 3,5,7-Tribromoindole
Tatsuo Higa and Paul J. Scheuer*
*Department of Chemistry, University of Hawaii at Manoa, 2545 Tha Mall, Honolulu,
Hawaii 96822-2275, U.S.A.
Abstract
We synthesized 6-bromo-3-chloro- and 3,5,7-tribromoindole, two marine metabolites first isolated from the invertebrate Ptychodera flava laysanica (Hemichordata).
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■ Biomimetic Synthesis of the Dibenzazonine Alkaloid Laurifonine
S. Morris Kupchan,* Chang-Kyu Kim, and Katsuji Miyano
*Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, U.S.A.
Abstract
A facile and efficient biomimetic synthesis of laurifonine (9a) is described. Reduction of (±)-O-methylflavinantine (5a) with sodium borohydride yielded a mixture of the epimeric dienols 6a, in 83% yield. Treatment of the dienol mixture with boron trifluoride-etherate followed by hydrogenation over platinum in methanol gave laurifonine (%, 81%). When a mixture of (±)-proerythrinadienols (2a) was subjected to acid-catalyzed rearrangement, the (±)-desoxyaporphine 4 was obtained, in 85% yield. Possible biogenetic implications of the observations are discussed.
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■ A Simple and Stereospecific Synthesis of Diterpene Alkaloid Internediate
Tetsuji Kametani,* Yasuyuki Kato, Toshio Honda, and Keiichiro Fukumoto
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Thermolysis of l-cyano-5-methoxy-l-(4-methoxycarbonyl-4-vinylpentyl)benzocyclobutene (7) gave (±)-4aα-cyano-6-methoxy-lα-methoxycarbonyl-lβ-methyl- 1,2,3,4,4a,9,10,10a-octahydrophenanthrene (9), which on reduction afforded (±)-16,17-imino-16-oxo-12-methoxypodocarpane-8,11,13-triene (10).
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■ A Total Synthesis of Naucléfine
Tetsuji Kametani,* Mitsuhiro Takeshita, and Masataka Ihara
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
A total synthesis of naucléfine (1) was accomplished by condensation of tryptamine with the lactone (16). prepared from nicotinonitrile (5), followed by cyclisation of the 7-azaisocarbostyril (8).
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■ Synthesis and Structure of Yohimbine Alkaloids
László Töke and Csaba Szántay*
*Institute for Organic Chemistry, Technical University Budapest, H-1521 Budapest, P.O. Box 91Gellért tér 4, Hungary
Abstract
New methods for the synthesis of yohimbine alkaloids — including both the normal and allo type — have been developed. The structure of alloyohimbine has been revised and some unnatural stereoisomers of yohimbine have also been obtained.
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■ A Review on the Conformational Aspects in the 1,3-Dioxane System
Marc J. O. Anteunis,* Dirk Tavernier, and Frans Borremans
*Laboratory for NMR Spectroscopy, Department of Chemistry, State University of Gent, Krijgslaan 271 (S.4bis), B-9000 Gent, Belgium
Abstract
Conformational Aspects of the 1,3-dioxane System.
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■ Flavonoids: Chemistry and Biochemistry
Naotaka Morita* and Munehisa Arisawa
*Faculty of Pharmaceutical Sciences, ToyamaUniversity, Gofuku 3190, Toyama 930-8555, Japan
Abstract
The carbon skeletons of the flavonoids are C6-C3-C6 units which called A, C, and B ring, respectively. Flavonoids, in their occurrence, represent a very large number of types with different properties. In this review, we wish to express the identification of this compounds and the flavonoids as taxonomic markers.
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■ A Review of Selected Potential Anticancer Plant Principles
Geoffrey A. Cordell and Norman R. Fransworth*
*Department of Pharmacognosy and Pharmacology, College of Pharmacy, University of Illinois at the Medical Center, Chicago, IL 60612, U.S.A.
Abstract
A review of some recent work on anticancer compounds from plants is presented.
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■ Studies on Indole Alkaloid Biosynthesis. Part II. Alkaloids Lacking the Normal Tryptophan Side Chain
James P. Kutney*
*Department of Chemisry, University of British Columbia, Vancouver 8, V5T 1W5
, Canada
Abstract
A summary of experiments relating to the biosynthesis of apparicine (II) and uleine (I) is presented. These alkaloids which lack the two carbon unit normally derived from tryptophan provide an interesting comparison with the Aspidosperma and Iboga bases for which a considerable amount of biosynthetic data has been accumulated. It is shown that tryptophan is utilized by the plant (Aspidosperma pyricollum) to provide the indole unit and the one carbon bridge between the β-position of the indole and the basic nitrogen atom in apparicine. Secodine is also incorporated intact into this alkaloid but the levels of incorporation are low. Interpretation of these results and their implications for future experiments are also provided. Preliminary experiments relating to the biosynthesis of olivacine (III, R = H; R’ - CH3) and guatambuine (XV) are presented.