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. 27, No. 1, 1988
Published online:
■ Hetisine Derivatives, Part 2: Novel Rearrangement of 11-Dehydrohetisine and 2,11-Didehydrohetisine
Balawant S. Joshi, Jan A. Glinski, Kottayil I. Varughese, and S. William Pelletier*
*Department of Chemistry, Institute for Natural Products Research, The University of Georgia, Chemistry Building, Athens, Georgia 30602-2556, U.S.A.
Abstract
Heating 11-dehydrohstisine (2) with sulfuric acid gave the rearragement produot 9. belongs to the orthorhombic space group P212121. 2,11-Didehydrohetisine (3) likewise afforded the rearranged triketone (10). The structure of the latter was confirmed by oxidation of 9 with pyridinium chlorochromate to 10.
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■ Reactions of Triethil(1-methyl-2-indolyl)borate with N-Carbophenoxypyridinium Derivatives
Minoru Ishikura and Masanao Terashima*
*Faculty of Pharmaceutical Scicences, Higashinihonngakuen University, 1757 Kanazawa, Toubetu-cho, Ishikari-gun, Hokkaodo 061-0212, Japan
Abstract
The reaction of triethyl(1-methyl-2-indolyl)borate with several N-carbophenoxypyridinium derivatives afforded 3-substituted 2-ethyl-1-methylindoles in the absence of copper(I) ion, while 3-substituted 1-methylindoles were obtained in the presence of copper(I) ion.
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■ Convenient Method for the Chemoselective and Regioselective Reduction of Oxiranes with Sodium Borohydride in Single Solvent
Atushiro Ookawa, Masaya Kitade, and Kenso Soai*
*Department of Applied Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka 1-3, Shinjuku-ku, Tokyo 162-8601, Japan
Abstract
Chemo- and regio-selective reduction of oxiranes to the corresponding alcohol are performed in high yields with sodium borohydride in single solvent (ethanol or 2-propanol).
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■ Molybdenum-promoted Reactions of 7-Oxabicyclo[2.2.1]heptadiene and Derivatives
Chia-Hsing Sun and Tahsin J. Chow*
*Institutue of Chemistry, Academia Sinica, 128, Yan-Chiu-Yuan Road, Sec II, Nankang, Taipei,11529, Taiwan, R.O.C.
Abstract
The reactions of 2,3-bis(methoxycarbonyl)-7-oxabicyclo-[2.2.1]heptadiene (1a) and related compaunds 1b, 1c, and 2 with molybdenum carbonyl complexes are examined at two different temperatures.In refluxed cyclohexane, reactions of 1a-c with hexacarbonylmolybdenum produce mainly the corresponding derivatives of dimethyl phthalate (3a-c) and 3,4-bis(methoxycarbonyl)furan (4a-c), while the reaction of 2 produces naphthalene and 1-naphthol. At room temperature, reactions of 1a,b with tris(acetonitrile)tricarbonylmolybdenum yield the dimer ketons 5a,b in addition to 3a,b and 4a,b, while the reacticn of 2 produces naphthalene as the only product. The mechanism for the generation of 3, 4, and 5 is rationalized as going through complex intermediate with structure of a molybdenum chelatea by 1.
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■ Formation and Reaction of Mesoionic Imidazolo[2,3-b][1,3]thiazines and [1,2,4,6]Thiatriazino[3,2-b][1,3]thiazin-4-one 2,2-Diosides from 2-Arylimino-1,3-thiazines
Mitsuhiro Ichinari, Tomohiro Sato, and Yoshio Hayase
*Aburahi Laboratories, Shionogi & Co. Ltd., Gotanda, Koka-cho, Koka-gun, Shiga 520-3423, Japan
Abstract
Two regioisomers of mesoionic imidazolones, obtained from the reaction of 2-arylimino-1,3-thiazines with chloroacetyl chloride (CAC), gave pyridones or pyrroles upon reaction with dimethyl acetylenedicarboxylate (DMAD). Also, 2-arylimino-1,3-thiazines gave mesoionic 1,2,4,6-thiatriazin-3-one 1,1-dioxides by reaction with chlorosulfonyl isocyanate (CSI), although only one regioisomer was obtained.
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■ Synthesis of (±)-Lasubine I
Hugo Ent, Henk de Koning, and W. Nico Speckamp*
*Laboratory of Organic Chemistry, Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands
Abstract
Using N-acyliminium cyclization as a key-step, the total synthesis of (±)-lasubine I has been achieved in six steps starting from veratraldehyde.
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■ Chemical and Catalytic Reductive Isomerization of [1,3]Oxazino[2,3-a]isoquinolines to [1,3]Oxazino[3,2-b]isoquinolines
Francesco Campagna,* Angelo Carotti, and Giovanni Casini
*Dipartimento Farmaco-Chimico, Università di Bari, Via Amendola 173, 70126 Bari, Italy
Abstract
The title reductive isomerization leading to 7, which contain a new heterocyclic ring system, has been carried out with Pd on C and more efficiently with NaBH4. A possible pathway for the formation of 7 as well as of other hydrogenolysis products is discussed.
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■ An Improved Synthesis of (+)-Heliotridine
Shinzo Kano,* Yoko Yuasa, and Shiroshi Shibuya
*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan,
Abstract
An alternative synthesis of (+)-heliotridine was achieved from 7-hydroxy-1-methylene-hexahydro-3H-pyrrozin-5-one. through conversion of exo-methylene to allylic alcohol part.
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■ Palladium-catalyzed Cross-coupling of Aryl Iodides with Ethyl 2-Ethoxy- and 3-Ethoxyacrylate
Takao Sakamoto, Yoshinori Kondo, Yoshitomo Kashiwagi, and Hiroshi Yamanaka*
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
The cross-coupling of iodobenzenes with ethyl 2-ethoxy- and 3-ethoxyacrylate in the presence of palladiumcharcoal gave ethyl α-ethoxy- and β-ethoxycinnamates in moderate yields. The cross-coupling of N-heteroaryl iodides with the same acrylates was alsc described.
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■ β-Elimination of the Pyrazinylsulfinyl Group — Preparation of Cinnamonitriles
Akihiro Ohta,* Kumi Okimura, Yoshiko Tonomura, Masakatsu Ohta, Naoki Yasumuro, Ritsuko Fujita, and Makoto Shimazaki
*Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
As a new leaving group for the β-elimination of sulfoxides, the pyrazinylsulfinyl group was introduced. Using this leaving group, some cinnamonitriles were prepared from the corresponding benzyl bromides and chloroacetonitrile.
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■ Synthesis of 1,4-Dihydropyridines by Cyclocondensation Reactions
Alvils Sausins and Gunãrs Duburs*
*Institute of Organic Synthesis, Academy of Science of the Latvian SSR, 21 Aizkraukels, Riga-6, Latvia, Latvia
Abstract
This review surveys the latest developments pertaining to the preparation of 1,4-dihydropyridines using Hantzsch synthesis and other cyclocondensation reactions.
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■ Reactions of 1,4-Dihydropyridines
Alvils Sausins and Gunãrs Duburs*
*Institute of Organic Synthesis, Academy of Science of the Latvian SSR, 21 Aizkraukels, Riga-6, Latvia, Latvia
Abstract
Recent studies of chemical reactivity of 1,4-dihydropyridines are surveyed.