Regular Issue

Vol. 16, No. 10, 1981

20 data found. 1 - 20 listed
Communication | Regular issue | Vol 16, No. 10, 1981, pp.1647-1650
Published online:
DOI: 10.3987/R-1981-10-1647
Reduction of Spirohydantoins with Lithium Aluminium Hydride: Synthesis of Spiroimidazolidin-2’-ones and Spiroimidazolidines

Elena de la Cuesta, Palomo Ballesteros, and Gregorio G. Trigo*

*Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain

Abstract

The behaviour of some spirohydantoins against reduction with lithium aluminium hydride as well as the influence of the N3’-substituent on this reaction are analized. N3’-Unsubstituted spirohydantoins yielded the corresponding spiroimidazolidin-2’-ones, while N3’-substituted spirohydantoins originated the spiroimidazolidines. Isomeric (α and β) spiroimidazolidin-2’-ones can be prepared by reduction of the suitable epimeric (α and β) spirohydantoins.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1651-1658
Published online:
DOI: 10.3987/R-1981-10-1651
Substitutent Effects on the Course of the Reductive Acylation of Penicillin Sulfoxide Derived Sulfenates

Leilani V. Kapili, Michael S. Kellogg,* and Robert J. Martingano

*Central Research Division, Pfizer Inc., Eastern Point Road, Groton, Connecticut 06340, U.S.A.

Abstract

Reductive acylation of penicillanate sulfoxide derived sulfenates with trivalent phosphorous compounds and acetic anhydride has been shown to give β-lactam products resulting from either oxygen or sulfur transfer to phosphorous dependent on the substituent at the C-6 position of the penicillanate.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1659-1664
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DOI: 10.3987/R-1981-10-1659
Synthesis of Pentacyclic Structure of Griseusin A

Kazuhisa Masamoto, Yoshio Takeuchi, Kei Takeda, and Eiichi Yoshii*

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

A synthetic method of the framework of griseusin A was presented. The key step involved an intramolecular ketalization of the δ,δ’-dihydroxyketone derivative which was prepared from 2-allyl-3-bromo-1,4-dimethoxynaphthalene.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1665-1668
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DOI: 10.3987/R-1981-10-1665
Base-Promoted Isomerization of 4-(Pyrrolylmethyl)-1,2,3,6-tetrahydropyridines

Joan Bosch,* David Mauleón, and Ricardo Granados

*Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, Av. de Joan XXIII, s/n, 08028 Barcelona, Spain

Abstract

The base-promoted isomerization followed by acetic acid treatment of two 4-(pyrrolylmethyl)-1,2,3,6-tetrahydropyridines is studied. 1-Methyl-4-(1-pyrrolylmethyl)-1,2,3,6-tetrahydropyridine (3) gave a mixture of the methanopyrrolodiazocine 1 and pyrrole, the latter arising from a fragmentation reaction. 1-Methyl-4-(1-methyl-2-pyrrolylmethyl)-1,2,3,6-tetrahydropyridine (4) afforded a mixture of recovered tetrahydropyridine and a 4-methylenepiperidine 5 instead of the cyclization product 2.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1669-1671
Published online:
DOI: 10.3987/R-1981-10-1669
A Simultaneous Detemination of Enantiomeric Purity and Chirality of a Certain Cyclic Enone Relating to the Gibbane Framework

Seiichi Takano,* Chiyoshi Kasahara, and Kunio Ogasawara

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

A simultaneous determination of enantiomeric purity and chirality of a certain cyclic enone relating to the gibbane framework has been achieved using 1H-nmr spectroscopy.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1673-1676
Published online:
DOI: 10.3987/R-1981-10-1673
Synthetic Approach to Diterpene Alkaloids — A Simple and Novel Synthesis of the A, B, C and D Ring Part from 1-Benzyl-1,2,3,4-tetrahydroisoquinoline

Tetsuji Kametani,* Toshio Honda, Keiichiro Fukumoto, Masahiro Toyota, and Masataka Ihara

*Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan

Abstract

The synthesis of the A,B,C and D ring part (13) of diterpene alkaloid atisine (5) from 1-benzyl-1,2,3,4-tetrahydroisoquinoline (6) by use of an intramolecular Diels-Alder reaction is described.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1677-1680
Published online:
DOI: 10.3987/R-1981-10-1677
The Synthesis of 9H-Imidazo[1,2-a][1,3]diazepines

Takushi Kurihara,* Tsutomu Tani, and Keiko Nasu

*Faculty of Pharmaceutical Science, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan

Abstract

Ethyl 7-acetyl-2,3-diphenyl-9H-imidazo[1,2-a][1,3]diazepine-5-carboxylate (8) and its acetate (7) were synthesized via the ring-expansion reaction of ethyl 5a-acetyl-4a,5a-dihydro-2,3-diphenyl-5H-cyclopropa[4a,5a]imidazo[1,2-a]pyrimidine-4a-carboxylate (2).

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1681-1685
Published online:
DOI: 10.3987/R-1981-10-1681
Casuarictin and Casuarinin, Two New Ellagitannins from Casurina stricta

Takuo Okuda,* Takashi Yoshida, and Mariko Ashida

*Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

Two new ellagitannins, casuarictin (1) and casuarinin (2) were isolated from the leaves of Casuarina stricta, and their structures were elucidated. Pedunculagin (3) and tellimagrandin-I were also isolated, and the structure 3 including S-configurations of hexahydroxydiphenoyl groups was established.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1687-1691
Published online:
DOI: 10.3987/R-1981-10-1687
Novel NADH Models. Steroids Bearing Pendent 1,4-Dihydronicotinamides

Piet C. Keijzer, Adriaan Oudeman, Alida M. v. d. Burg, and Upendra K. Pandit*

*Organic Chemistry Laboratory, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands

Abstract

Steroids bearing 1,4-dihydronicotinamides at the 3-position have been synthesized and studied as potential chiral reducing agents.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1693-1696
Published online:
DOI: 10.3987/R-1981-10-1693
Synthesis of 3,4-Dihydroquinazolines via Cyclic N-Diazonium Ions

Richard Kreher* and Udo Bergmann

*Institut für Chemie, Medizinische Hochschule Lübeck, Ratzeburger Allee 160, D-2400, Germany

Abstract

The condensation of 2-azidomethylanilines with aromatic aldehydes leads to tne formation of the corresponding azomethines. Treatment with tetrafluoroboric acid results in the generation of phenylogous azidomethyl-iminium salts giving rise to the formation of 2-aryl-3,4-dihydroquinazolines. Cyclic N-diazonium ions are involved as reactive intermediates and synthetic precursors for the annelation of the 6-membered nitrogen heterocycle.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1697-1700
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DOI: 10.3987/R-1981-10-1697
Reactions of Indolizines with Tropone

Yoshiro Yamashita, Daisuke Suzuki, and Mitsuo Masumura*

*Department of Applied Chemistry, Faculty of Engineering, University of Tokushima, Minamijosanjima-cho, Tokushima 770-8506, Japan

Abstract

Reactions of indolizine derivatives with tropone gave the Michael type adducts 2 and 2-indolizin-3-yltropone derivatives 3. The tropones 3 were formed by dehydrogenation of the adducts.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1701-1704
Published online:
DOI: 10.3987/R-1981-10-1701
Synthesis of New Macrocyclic Polythiaether

Hisashi Fujihara, Koji Imaoka, Naomichi Furukawa, and Shigeru Oae*

*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan

Abstract

Synthesis of a new macrocyclic polythiaether (12) which is easily obtained in a good yield via 2,6-dithia-4-spiroheptane (6) is described. Several reactions of pentaerythrityl bromide (1) with nucleophiles and a few ring opening reactions of 6 with methyl iodide are also described.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1705-1712
Published online:
DOI: 10.3987/R-1981-10-1705
2-Methylene-3-phenacylbenzothiazoline: Dimerization and Reactions with Electron-deficient Acetylenes and Olefins

Otohiko Tsuge,* Minoru Tanaka, Hiroshi Simoharada, and Michihiko Noguchi

*Research Institute of Industrial Science, Faculty of Engineering, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan

Abstract

On treatment with triethylamine in acetonitrile at 0°C, 2-methy-3-phenacylbenzothiazolium bromide gave a dimer of 2-methylene-3-phenacylbenzothiazoline in a quantitative yield. The methylene base, generated in situ, reacted with electron-deficient acetylenes and olefins to give 3-substituted 2-phenylpyrrolo[2,1-b]benzothiazole via a Michael type adduct; in some cases Michael type adducts were isolated. On the other hand, the methylene base reacted with tetracyanoethylene to give 2-butadienylidenebenzothiazoline derivative, which on heating in acetic anhydride afforded 1-benzoyl-2-cyanopyrrolo[2,1-b]benzothiazole with the elimination of malononitrile.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1713-1717
Published online:
DOI: 10.3987/R-1981-10-1713
A Selective One-step Introduction of Hydroxylic Functions at the C-5 and C-7 Positions of 20(S)-Camptothecin, an Alkaloid Having Antitumor Activity

Tadashi Miyasaka,* Seigo Sawada, and Ken’ichiro Nokata

*School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan

Abstract

20(S)-Camptothecin was selectively hydroxymethylated at the C-7 position by a simple process using hydrogen peroxide-methanol in the presence of ferrous ion as the radical source. Formation of diastereomers of 5-hydroxycamptothecin was observed by using ammonium persulfate-bromoacetic acid in the presence of ferrous or silver ion. The hydroxylic compounds prepared by the processes were converted further into acyloxyl, alkoxyl, and carboxylic acid derivatives.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1719-1721
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DOI: 10.3987/R-1981-10-1719
Chemical Modification of Antitumor Alkaloid Camptothecin. Acid-Catalyzed Conversion of 7-Hydroxymethylcamptothecin into the Aldehyde and Its Acetals

Tadashi Miyasaka,* Seigo Sawada, and Ken-ichiro Nokata

*School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan

Abstract

Camptothecin-7-carbaldehyde (3) was prepared from 7-hydroxymethylcamptothecin (2) by treatment with such cationoid agent as sulfuric acid, acetic acid, p-toluenesulfonyl chloride, phosphoryl chloride, thionyl chloride, or triphenylphosphine-carbon tetrachloride. On heating with sulfuric acid in an alcoholic solution, 2 afforded 7-alkoxymethylcamptothecin (4) and 7-dialkoxymethylcamptothecin (5), the product-ratio depending upon the acid-concentration.

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Communication | Regular issue | Vol 16, No. 10, 1981, pp.1723-1725
Published online:
DOI: 10.3987/R-1981-10-1723
Structure of Deoxyjesaconitine. A New Diterpene Alkaloid from Aconitum subcuneatum Nakai

Hideo Bando, Yoshio Kanaiwa, Koji Wada, Takao Mori, and Takashi Amiya*

*Hokkaido College of Pharmacy, 7-1 Katsuraoka-cho, Otaru 047-02, Japan

Abstract

A new diterpene alkaloid, deoxyjesaconitine, was isolated from Aconitum subcuneatum and its structure was determined on the basis of spectral data. This compound along with deoxyaconitine and hypaconitine was purified with high performance liquid chromatography, and 13C-NMR spectra of those compounds were measured to afford the relationship with each compound.

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Report | Regular issue | Vol 16, No. 10, 1981, pp.1727-1733
Published online:
DOI: 10.3987/R-1981-10-1727
Structure and Absolute Configuration of Serpenticine, a New Anhydronium Base from Rauwolfia vomitoria Afzuelia

Abdul Malik, Nighat Afza, and Salimuzzaman Siddiqui*

*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan

Abstract

The structure and absolute configuration 9 of serpenticine, a new anhydronium base isolated from Rauwolfia vomitoria Afz., has been determined with the aid of UV, IR and 13C-nmr spectral data of the base along with ORD, proton nmr and high resolution mass spectra of its tetrahydro product 8.

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Report | Regular issue | Vol 16, No. 10, 1981, pp.1735-1738
Published online:
DOI: 10.3987/R-1981-10-1735
A New Product in the Photooxidation of Berberine: A Lactamic Aldehyde

M. Leonor Contreras* and Roberto Rozas

*Department of Chemistry, Facluty of Science, University of Santiago of Chile, Casilla 56559, Santiago-2, Chile

Abstract

Berberinium chloride (1) unsensitized photooxidation in the presence of sodium methoxide affords the lactamic aldehyde (2) in contrast to the already informed sensitized reaction that furnishes the betaine (3).

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Review | Regular issue | Vol 16, No. 10, 1981, pp.1739-1754
Published online:
DOI: 10.3987/R-1981-10-1739
The Conformational Behavior in Thia- and Dithiametacyclophanes

Yee-Hing Lai*

*Department of Chemistry, University of Victoria, Victoria, BC V8W 3V6, Canada

Abstract

Thia- and dithiametacyclophanes have been shown to undergo several types of interesting conformational behavior. The coalescence temperature method has been widely used to estimate the various conformational energy barriers. Dithia[n]metacyclophanes exhibit a unique flipping process, the barrier of which largely depends on the substituent at the [n+6]-position. An inversion process is common among thia- and dithia[m.n]metacyclophanes (m = n or m ≠ n). However, substituent(s) at the 9- and/or 18-position(s) of dithia[3.3]metacyclophanes results in variability of the conformer preferred. Most medium-sized dithiametacyclophanes seem to be conformationally very mobile but three dithia[3.1.3.1]metacyclophanes are known to demonstrate a novel “twist-inversion” fluxional behavior.

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Review | Regular issue | Vol 16, No. 10, 1981, pp.1755-1771
Published online:
DOI: 10.3987/R-1981-10-1755
Ring Transformations of Heterocycles over Synthetic Zeolites

Yoshio Ono*

*Department of Chemical Technology, Faculty of Engineering, Tokyo Institute of Technology, 2-12-1,Oh-Okayama, Meguro-ku, Tokyo 152-8552, Japan

Abstract

Synthetic zeolites are found to be very effective and selective catalysts for the vapor phase ring transformations of oxygen-containing heterocycles into nitrogen or sulfur-containing heterocycles. For example, tetrahydrofuran is converted into pyrrolidines and tetrahydrothiophene, while γ-butyrolactone is converted into pyrrolidinones and γ-thiobutyrolactone by the reactions with primary amines and hydrogen sulfide, respectively. The most effective catalysts differ with reactions. For the reaction of tetrahydrofuran with ammonia, acidic zeolites such as HL(proton form of L-type zeolite) are most effective, while for the reaction of γ-butyrolactone with hydrogen sulfide, basic zeolites like CsY(CS+ exchanged Y-type zeolite) are highly active. The kinetics of the ring transformations are studied and the reaction mechanisms are discussed.

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20 data found. 1 - 20 listed