HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Special Issue
Bernhard Witkop's Special Issues, Vol. 49, No. 1, 1998
Published online:
■ A New Cleavable Carbene-generating Reagent with 3-Phenyl-3-trifluoromethyldiazirine Photophore
Uwe Kempin, Yuichi Kanaoka, and Yasumaru Hatanaka*
*Research Institute for Wakan-Yaku, Toyama Medical and Pharmaceutical University, Sugitani 2630, Toyama 930-0194, Japan
Abstract
Synthesis of a 3-phenyl-3-trifluoromethyldiazirine derivative having a clevable 1,2-diol moiety for photocross-linking technique is described. An ester of cinnamic acid derivative was prepared by the Witting reaction of 2-methoxy-4-[3-trifluoromethyl-3H-diazirin-3-yl]benzaldehyde which can be readily prepared by the Friedel-Crafts reaction of corresponding phenyldiazirine. The osmium oxidation of the olefinic bond gave the desired diol derivative, ethyl 2,3-dihydroxy-3-[2-methoxy-4-(3-trifluoromethyl-3H-diazirin-3-yl)phenyl]propionate, in a high yield. The cleavability of the diol group was confirmed by the conventional periodate oxidation to give the starting aldehyde.
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■ Difference in Guest Binding Capability between Cyclodextrins Having an Acetylamino Moiety at Primary- and Secondary-Hydroxyl Sides: The Effect of Ring Distortion
Iwao Suzuki,* Yoshinobu Sakurai, Koki Obata, Tetsuo Osa, and Jun-ichi Anzai
*Faculty of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
Abstract
A γ-cyclodextrin (γ-CyD) derivative prossessing an acetylamino moiety at its secondary hydroxyl side can bind only one guest molecule into its distorted cavity. The γ-CyD derivative could discriminate the chirality of some terpene guests in binding strength.
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■ Reduction of Uracil Derivatives with an NADH Model, 1-Benzyl-1,4-dihydronicotinamide
Kosaku Hirota,* Keiko Kubo, Yukio Kitade, and Hironao Sajiki
*Laboratory of Medicinal Chemistry, Gifu Pharmaceutical University, Mitahora-higashi, Gifu 502-8585, Japan
Abstract
Among various C(5)-, N(1)-, and N(3)-substituted uracils, 1-substituted 5-nitrouracil derivatives were reduced by an NADH model, 1-benzyl-1,4-dihydronicotinamide, to give 5,6-dihydro-5-nitrouracil derivatives, the formation of which was accelerated to a large extent by the use of Mg2+ as a catalyst.
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■ Acetylcholinesterase Inhibiting Triterpenoidal Alkaloids from Buxus hyrcana
Atta-ur-Rahman,* Shehnaz Parveen, Asaad Khalid, Afgan Farooq, S. A. Majid Ayatollahi, and M. Iqbal Choudhary*
*International Centre for Chemical Sciences, H. E. J. Research Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan
Abstract
Buxus hyrcana of Iranian origin has yielded two new trierpenoidal alkaloids (-)-hyrcanine (1) and (+)-homomoenjodaramine (2) along with a previously known compound, moenjodaramine (3), which has been obtained for the first time from this species. Compounds (2) and (3) were found to be potent acetylcholinesterase inhibitors.
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■ Synthesis and Biological Evaluation of 14-Alkoxymorphinans. 16. 14-O-Alkyl Derivatives of the μ-Opioid Receptor Antagonist Cyprodime
Helmut Schmidhammer,* Roland Krassnig, Elisabeth Greiner, and John R. Traynor*
*Institute of Pharmaceutical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
Abstract
The 14-O-benzyl derivatives of cyprodime and 3-hydroxycyprodime (compounds (5) and (6), respectively) were synthesized in several steps from 3-desoxynaltrexone (2a) and naltrexone (2), respectively. In the mouse vas deferens preparation it was found that a 14-O-benzyl group could enhance μ opioid receptor affinity in cyprodime while the μ affinity of 3-hydroxycyprodime was not changed.
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■ Pictet-Spengler Reactions of Nb-Hydroxytryptamines and Their Application to the Synthesis of Eudistomins
Tohru Hino and Masako Nakagawa*
*Faculty of Pharmaceutical Sciences, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba-shi 263-8522, Japan
Abstract
Methods for preparing Nb-hydroxytryptamines, their Pictet-Spengler reactions with various aldehydes via nitrones, and their asymmetric inductions are reviewed. Syntheses of oxathiazepine-containing eudistomins and related natural products which incorporate these reactions are also reviewed.
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■ Survey of Oxygenated 2,11-Cyclized Cembranoids of Marine Origin
Patrick Bernardelli and Leo A. Paquette*
*Evans Chemical Laboratories, The Ohio State University, Columbus, OH 43210, U.S.A.
Abstract
The structure, source, and biological activities of the many known members of the four classes of oxygenated 2,11-cyclized cembranoid natural products are compiled in tabular form. The cladiellins, briarellins, asbestinins, and sarcodictyins have been purposefully organized to highlight biological activity interrelationships.
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■ Synthesis of 1,3,4-Thiadiazines and 1,3,4-Oxadiazines
Ho Sik Kim* and Yoshihisa Kurasawa*
*School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo 108-8641, Japan
Abstract
This review summarizes several methods for the synthesis of 1,3,4-thiadiazines and 1,3,4-oxadiazines reported in 1960s-1990s.
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■ Stable Heterocyclic Five-membered Azomethine Imines: Azolium N-Imides, Triazolidinium and Pyrazolidinium Ylides
Ludmila L. Rodina,* Arne Kolberg, and Bärbel Schulze
*St.-Petersburg State University, Department of Organic Chemistry, 199004 St.-Petersburg, Srednij pr. 41, Russia
Abstract
This review described two types of stable heterocyclic five-membered azomethine imines. Firstly, aromatic stabilized azomethine imines (azolium N-imides), containing the C-N-bond in a heteroaromatic five-membered ring. Secondly, non-aromatic stabilized compounds incorporating two N-atoms of the azomethine imine moiety in a five-membered ring and an exocyclic C-atom — triazolidione azomethine imines (or triazolindione ylides), pyrazolidone azomethine imines, and their analogues. Their preparation, structures, and some reactions are considered.