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
Derek H. R. Barton's Special Issues, Vol. 28, No. 2, 1989
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■ Radical Cyclization of Allylic Haloacetamides. A Route to cis-Fused 2-Pyrrolidones and Piperidones
Gilbert Stork* and Robert Mah
*Department of Chemistry, Columbia University, 3000 Broadway, Mail Code 3114, New York, New York 10027, U.S.A.
Abstract
A variety of N-protected haloacetamides undergo efficient radical cyclization to produce N-protected lactams. The protecting groups can be removed under a range of different conditions.
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■ Synthesis of a Novel Furan-Containing Tricyclic Prostacyclin Analogue
Yasuhiro Torisawa, Katsumi Satoh, and Shiro Ikegami*
*Faculty of Pharmaceutical Sciences, Teikyo University, 1091-1, Sagamiko, Kanagawa 199-0195, Japan
Abstract
Described herein is a synthesis of the new prostacyclin analogue (2a), which contains a highly strained tricyclic furan skeleton related to isocarbacyclin (1).
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■ Synthesis and Rections of 2,3-Dihydrocyclohepta[b][1,4]thiazines and 2,3-Dihydro-1H-cyclohepta[b]pyrazines
Tetsuo Nozoe,* Sumio Ishikawa and Kimio Shindo*
*Department of Chemistry, Faculty of Science, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan
Abstract
The reaction of 2-methoxytropone with ethylenediamine gave 2-(2-aminoethyl)aminotropone and 2,2’-(1,2-ethanediamino)-bis(tropone), and the former afforded 2,3-dihydro-1H-cyclohepta[b]pyrazine (13) on heating. N-Methyl compound 14 of 13 was also obtained by the similar method. 14 was led to the dimethyl cation 18b, which gave exclusively 7-bromo compound 24 with bromine in acetic acid. 18b and 24 rearranged to 1,2,3,4-tetrahydro-1,4-dimethylguinoxaline-6-arbaldehyde with alkali, while 13 rearranged to 1-phenylimidazolin-2-one on treatment with H2O2. The reaction of 2-chlorotropone with 2-aminoethanethiol rapidly afforded 2-(2-aminoethylthio)tropone (35a), which gradually changed to 2-[2-(2-troponyl)thioethylamino]tropone (37a) and N,N’-bis(2-troponyl)-2-aminoethanedisulfide (39a) via unstable 2-(2-mercaptoethyl)-aminotropone (38a). Hydrochloride of 35a gave, upon heating, 2,3-dihydrocyclohepta[b][1,4]thiazine (15), which gave N-methyl cation 40 on treatment with magic methyl. 40 gradually changed with cold alkali to the disulfide 39b, via 35b, 37b, and 38b, in a manner similar to the case of their parent compounds (35a, 37a, and 38a). Possible pathways of these reactions, especially the facile exchange of the difunctionalized side-chains, are discussed.
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■ Correlation between Albanol B and Mulberrofuran I, and Structure of Mulberrofuran S, Novel 2-Arylbenzofuran Derivative
Yoshio Hano, Yoko Miyagawa, Mamiko Yano, and Taro Nomura*
*Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan
Abstract
Albanol B (1), obtained from the Morus root bark, was derived from mulberrofuran I (2) by silica gel column chromatography. The result suggests that 1 is an artifact derived from 2 through the autoxidation. From this point of view, mulberrofuran P (3) is also suggested to be an artifact from mulberrofuran S (4), a new 2-arylbenzofuran derivative, isolated from the reddish violet powder on the surface of the Morus root bark.
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■ N-(L-α-Aminoacyl) Derivatives of Methotrexate
H. T. Andrew Cheung,* Deborah K. Boadle, and Trung Q. Tran
*Department of Pharmacy, University of Sydney, Sydney, N. S. W., Australia
Abstract
Methotrexate di-t-butyl ester 3 was coupled with N-t-butyloxycarbonyl-L-leucine by the o-nitrophenyl ester and carbodiimide methods to give the di-t-butyl esters 5a-7a of 2-, 4-, and 2,4-di(N-t-butyloxycarbonyl-L-leucyl)methotrexate. The Corresponding L-alanyl analogues 5b-7b were also synthesised by the latter method. The positions of the acyl qroups were determined from 13C-nmr and uv data. Upon deprotection with trifluoroacetic acid, the 2-acyl products 5a and 5b yielded 2-L-leucyl- and 2-L-alanylmethotrexate 4a and 4b, but the 4-acyl analogues 6a and 6b gave decomposition products. The enzymic cleavaqe of the 2-(L-α-aminoacyl) prodrug derivatives 4a and 4b by porcine microsomal leucine aminopeptidase was followed by hiqh-pressure liquidchromatography (HPLC).
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■ Desulfhurisation of Penicillins with Triphenylstannane
Jack E. Baldwin,* Robert M. Adlington, Tae Won Kang, Lionel G. King, and Vipulkumar K. Patel
*Dyson Perrins Laboratory, Oxford University , South Parks Road, Oxford OX1 3QY, U.K.
Abstract
Reaction of penicillins (and a cephalosparin) with triphenylstannane provides a novel and efficient route to dethioazetidinones. A study on the mechanism of this process is described.
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■ Real Geometry of Molecules: Influential Substructure Information and Conformation Monitoring in Strained Sugars and Piperdines
J. E. Dubois* and A. Cossé-Barbi
*Institut de Topologie et de Dynamique des Systèmes, Associé au C.N.R.S., Universite Paris 7, 1, rue Guy de la Brosse 75005 Paris, France
Abstract
The real structure of certain piperidines and sugars is interpreted by comparing crystallographic information with its counterpart in usual standardized information. Local distortions are due either to stabilizations by stereoelectronic effect (anomeric effect) or to the relaxation of local steric effects (gem-6 structures). These effects can act either cooperatively or competitively. Their use, for purposes of prediction of static molecular geometry and of dynamic conformational behavior, is examined in this presentation. Coordination of effeets leads to excellent structural predictions for certain structure subpopulations. Structural knowledge at the level of substructure information appears to be transferable for high local constraints or special localized effects.
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■ Substitution Reactions of 2-Benzensulphonyl Cyclic Ethers with Silyl Enol Ethers Promoted by Aluminium Trichloride
Dearg S. Brown, Steven V. Ley,* and Maurizio Bruno
*Department of Chemistry, Imperial College of Science, Technology and Medicine, GB-London SW7 2AY, U.K.
Abstract
Several cyclic ether 2-benzenesulphones were shown to react with silyl enol ethers in the presence of AlCl3 to give the corresponding alkylated products in good yield. Where substitution occurred to give 2,6-disubstituted products there was a marked preference for the formation of the trans- isomer.
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■ Sesquiterpene Lactones from Dendroseris neriifolia
Verónica Campos, Jasmin Jakupovic, Magalis Bittner, Mario Silva,* and Tod Stussy
*Facultad de Ciencias Biológicas y de Recursos Naturales, Departamento de Botánica, Universidad de Concepción, Casilla 2407 Ap.-10, Conception, Spain
Abstract
A new eudesmaoolide, dendroserin ,was isolated from the aerial part of Dendroseris neriifolia Hook. and Arn. together with 8 α-hydroxyachillin, a known sesquiterpene lactone. The structures were elucidated by spectroscopic methods.
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■ Synthesis and Chiroptical Properties of 5α-Cholest-2-eno[2,3-b]pyrazine Derivatives
György Hajós* and Günther Snatzke
*Lehrstuhl für Strukturchemie, Ruhr-Universität Bochum, Postfach 10 21 48, D-4630 Bochum 1, Germany
Abstract
The steroidal pyrazine 5 has been synthesized from 5α-cholestane-2,3-dione. and its cd has been compared with that of octahydronaphtopyrazine 7 with C2-symmetry. The n-π* - Cotton effects of the parent compound have the same signs and magnitudes as for the homochirally analogous steroid, whereas the π-n*- Cotton effects differ. On the other hand, pyrazines containing substituents nonsymmetrically attached to the chrmophore show very similar Cotton effects. Assignment of transitions for the 2,3-dihydropyrazine chromophore could be made by comparison of the cd and uv spectra.
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■ Diazapolycyclic Compounds XXVIII. The Reaction of Acetylated Terpenoids with Diazaquinones
Fernando Gómez Contreras, Manuel Lora-Tamayo, and Ana Ma Sanz
*Centro de Química Orgánica ’Manuel Lora-Tamayo‘, Instituto de Química Médica, C. S. I. C., Calle Juan de Cierva, 3, E-28006 Madrid, Spain
Abstract
The [4+2] cycloaddition reactions of diazaquinones 1-3 with 1,3-dienic systems obtained via the enol acetylation of carbonylic terpenoids are described.
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■ Heterocyclic Polyethers Derived from D-Sorbitol and D-Mannitol as Hosts for Chiral Ammonium Salts
Elizabeth A. El’perina, Edward P. Serebryakov,* and Marina I. Struchkova
*Institute of Organic Chemistry, Russia Academy of Science, 117913, Moscow, Russia
Abstract
Coronands (3a) and (3b) derived from D-sorbitol display but poor or no recognition towards (R)- or (S)-α-phenylethylammonium hexafluorophosphates (PEA.HPF6) but selectively extract (R)- and (S)-enantiomers, respectively, of the α-phenylglycine methyl ester salt. All novel derivatives of D-mannitol (6,7a-e) show no chiral recognition towards PEA.HPF6 or PEA.HClO4, the complexing ability of podands 7a-e varying with the nature of side chains.
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■ Unusual Reactions of Steroidal and Non-steroidal 1,5-Dioximes. Stereochemistry and Mechanism of Formation of N-Hydroxypiperidine Analogues
Suresh K. Pradhan,* Krishnacharya G. Akamanchi, Pulukkunatt P. Divakaran, and Prakash M. Pradhan
*Pharmaceutical Division, Department of Chemical Technology, University of Bombay, Matunga Road, Bombay 400 019, India
Abstract
4,5-Secocholestane-3,5-dioxime on NaBH4 reduction gave N-hydroxy-3β-methyl-4-aza-5α-cholestane and N-hydroxy-3α-methyl-4-aza-5β-cholestane. The stereochemistry of the products was fully established by converting the N-hydroxy compounds to N-chloro compounds which resulted in 1H nmr signals separating out from the steroid envelope. The dioxime on reaction with NH2 OCH3 underwent a regiospecific replacement of the oxime at C-3 by an oxime ether. In both these reactions this and other 1,5 dioximes exhibit unique behaviour not shown by isolated oximes. Arguments are presented pin-pointing a single mechanism involving a “oxadiaza” intermediate lsomeric with the dioxime.
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■ Stereocontrolled Syntheses of Apartame [(S)-Asp-(S)-PhOMe] and Its (R)-Aspartyl Congener [(R)-Asp-(S)-PhOMe] via Nitrone Cycloaddition
David Keirs and Karl Overton*
*Departmentof Chemistry, University of Glasgow, Joseph Black Building, Glasgow G12 8QQ Scotland, U.K.
Abstract
The title compounds have been synthesised via cycloaddition of nitrones (3a,b,c) to 2-chloroacrylonitrile.
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■ Synthesis of 4-Highly Branched Imidazole Derivatives via Cine-Substitution and SRN1 Substitution of 5-Nitroimidazoles with Anions of Nitroalkanes
Michel P. Crozet,* Patrice Vanelle, Olivier Jentzer, and Michèle P. Bertrand
*CNRS, LASCO UA 109, Université d’Aix-Marseille III, Avenue Escadrille Normandie-Niemen 13397 Marseille Cedex 20, France
Abstract
Cine-substitution and SRN1 substitution of 1,2-dimethyl-5-nitroimidazole with the anions of secondary nitroalkanes provide a new and rapid synthesis of 4-highly branched imidazole derivatives in good yields. The mechanistic aspects of the involved reactions are discussed.
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■ Synthesis and Protonation of Dipyrrolo[1,2-a:2’,1’-c]pyrazines
Robert Buchan, Martin Fraser,* and Paul V. S. Kong Thoo Lin
*Department of Chemistry, The Robert Gordon’s Institute of Technology, St. Andrew‘s Street, Aberdeen AB1 1HG, Scotland, U.K.
Abstract
The dipyrrolol[1,2-a:2’,1’-c]pyrazines 3-9 were prepared by base catalysed cyclisation of the quaternary salt resulting from reaction of various 8-methyl-7-asaindolizines with an α-haloketone. Deuterium exchange and protonation were shown to occur preferentially at the 3(8)- and then 1(10)- positions.
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■ A Facile Synthesis of Phthalideisoquinolines by Decarboxylation of Phthalidecarboxylates in the Presence of Imine Methiodides
John Chiefari, Wit K. Janowski, and Rolf H. Prager
*School of Physical Sciences, Flinders University of South Australia, Bedford Park, South Australis 5042, Australia
Abstract
Deearboxylation of potassium phthalide-3-carboxylates in the presence of acyclic imine methiodides in DMSO leads mainly to 2-acylbenzamides, but with 3,4-dihydroisoquinolinium methiodides, a one step synthesis of phthalideisoquinilines is achieved in moderate yields.
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■ New Types of Steroidal Isoxazolidines
Mihailo Lj. Mihailovic,* Ljubinka Lorenc, Milica Rajkovic, Ivan Juranic, and Aleksandar Milovanovic
*Department of Chemistry, Faculty of Science, University of Belgrade, Studentski trg 16, P.O.Box 550, 11001 Belgrade, Serbia and Montenegro
Abstract
Transannular nitrone 1,3-dipolar cycioaddition performed with (Z)-3β-acetoxy-δ1(10)-unsaturated 5,10-secoketones 4a and 4b and N-methylhydroxylamine proceeds with acetic acid elimination to give mixtures of the respective δ1-unsaturated 3β,5β-epoxyimino compounds 7a and 7b, and δ3-unsaturated 1β,5β-epoxyimino derivatives 8a and 8b, while similar cycloaddition carried out with the (Z)-3β-hydroxy analogue 12 takes place without elimination at C(3) to produce only the 3β-hydroxy-1β,5β-epoxyimino compound 13. Under the same conditions, the corresponding 2,4-dien-1-ones 9a and 9b are formed as the minor products.
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■ An Expeditious Synthesis of 2-Dialkylamino-4-chloropyrimidines from Silylated Primary Enamines and Phosgeniminium Salts
Nadine Guillot, Zdenek Janousek, and Heinz G. Viehe
*Laboratoire de Chimie Organique de Synthése, Université de Louvain, Place Louis Pasteur 1, B-1348 Louvain-la-Neuve, Belgium
Abstract
Trlmethylsilyl-protected primary enamines 4 condense with two equivalents of phosgeniminium chloride (PI) to form 2-aza-1,5-dichloropentamethine cyanines 5. These versatile intermediates cyclize upon heating to 2-(dialkylamino)-5-alkyl-6-alyl-4-chloropyrimidines 6 via a loss of the corresponding alkyl chloride. The reactions are completely regiospecific and represent a new useful entry to pyrimidin neuclei.
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■ Cycloaddition Reactions Leading to Carbohydrate Derivatives. Part II. Hetero Diels-Alder Reactions of Monosaccharide 1,1-Dithiooxalates and O-Thioformates. A Comparative Study
Pál Herczegh, Martina Zsély, László Szilágyi, and Rezsö Bognár*
*Reseaech Group of Antibiotics, Hungarian Academy of Sciences, H-4010 Debrecen, Hungary
Abstract
A series of chiral dihydrothiopyran derivatives has been obtained in hetero Diels-Alder reactions of monosaccharide O-thioformates and 1,1-dithiooxalates with several butadienes. Diastereo- and regioselectivities of the reactions were studied.
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■ Asnipyrones A and B, Two Novel Metabolites from Aspergillus niger
Li Guang-yi, Jürgen Lenz, and Burchard Franck*
*Organisch-Chemisches Institut, Universität Münster, Orleansring 23, D-4400 Münster, Germany
Abstract
Two bright yellow coloured metabolites, named asnipyrone A C21H22O3 and asnipyrone B C20H20O3, have been isolated from Aspergillus niger strain DSM 21822. On the basis of chemical reactions and spectroscopical data their structures were derived as the phenyltrienyl-α-pyrones (1) and (2).
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■ A Novel Pathway to 11-Oxa Steroids. Syntheses of 11-Oxaesteradiol and a New Synthesis of 11-Oxa-1-dehydro-11-doexycortisol
Ch. R. Engel,* Ibrahim Halim Ibrahim, Debabrata Mukherjee, Robert Szöghy, and Vilas Shivram Salvi
*Département de Chimie, Faculté des Sciences et de Génie, Université Laval, Cité Universitaire, Québec, G1K 7P4, Canada
Abstract
The synthesis of 11-oxaestradiol, a product with antifertility activity but very low uterotropic potency, is reported. It was first prepared in moderate yield by a Dryden aromatization from 17β-acetoxy-11-oxaandrosta-1,4-dien-3-one and, secondly, from estrone or dehydroestrone, by a new and efficient route involving a photolytic chlorinating decarboxyiation of a 9-oxo-9,11-seco-11-acid and cyclization of the 9β-hydroxy-9,11-seco-11-nor-12-chloride derived from the degradation product. By the latter procedure, 11-oxa-1-dehydro-11-deoxycortisol and its acetate, antiinflammatory agents with no mineralocorticoid and, at the dose levels to be considered, insignificant glucocorticoid responses, were also prepared from 17,21-dihydroxylated 5α-pregnan-20-ones.
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■ Oligomeric Flavanoids. Part 6. Evidence Supporting the Inversion of Absolute Configuration at 3-C Associated with Base Catalyzed A-/B-Ring Interchange of Precursors Having 2,3-trans-3,4-cis-Flavan-3-ol Constituent Units
Jan P. Steynberg, Johann F. W. Burger, Desmond A. Young, Edward V. Brandt, and Daneel Ferreira*
*Department of Chemistry, Research Unit for Polyphenol and Synthetic Chemistry, University of Orange Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
Abstract
Whereas the enantiomeric 2,3-tans-3,4-trans-4-arylflavan-3-ols (10) and (12) as biflavanoid models are subject to stereospecific C-ring isomerization under base catalysis, those with 3,4-cis configuration (11) and (13) are transformed stereoselectively via intermediate quinonemethides (20) and (27) to form a range of analogous 4-arylflavan-3-ols with rearranged pyran heterocycles. The inversion of the absolute configuration a t 3-C in those isomers possessing interchanged resorcinol A- and pyrocatechol B-rings [eg. (28), (30) vs. (23), (25)] required by the mechanism for their formation, are unequivocally confirmed by comparison of the cd data of the different enantiomeric- and quasi-enantiomeric pairs.
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■ Conformational Analysis. 49. A Complete Conformational Analysis of the trans-2-(α-Hydroxybenzyl)thiane Sulfoxides
Ernest L. Eliel,* Edward M. Olefirowicz, Maria T. Alvarez, Derek J. Hodgson, and Debra K. Towle
*Laboratories of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, U.S.A.
Abstract
The relative stereochemistry of the title compounds has been determined by X-ray structure analysis of the R*S*R* diastereomer. The compound C12H16O2S crystallizes in the monoclinic space group P21/c with a = 14.161(8), b = 10.135(4), c = 15.999(7), β = 97.17(4)°, and V = 2278(3)Å3. Tnere are two crystallographically independent molecules in the cell, and a total of eight molecules per cell. Both independent molecules are present as the same diastereomer, but they undergo two different forms of intermolecular hydrogen bonding. Infrared analysis of this isomer in dilute solution shows intramolecular hydrogen bonding which is absent in the crystal. Both isomers were analyzed by proton and 13C nmr spectroscopy and their conformational energy profiles as a function of the Ph-C(6)-C(1)-H(1) torsion angle were assessed by MMP2 force field calculations. The energy profile shows an interesting interplay between torsional and hydrogenbonding forces.
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■ Use of the Barton Decarboxylation Procedure in Indole Alkaloid Chemistry
Philip Magnus,* Mark Ladlow, Chung Sook Kim, and Peter Boniface
*Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, U.S.A.
Abstract
L-Tryptophan was condensed with dimethyl α-ketoglutarate to give the tetracyclic amide (+) 8 and its diastereoisomer (-) 9. Conversion of (+) 8 into its derived N-hydroxy-2-thiopyridone ester 11 followed by t-butylthiol/hu gave (+) 12. This was converted into the desired tetracyclic amine (+) 2 in 30% overall yield. Similarly, starting with D-tryptophan gave (-) 2, thus allowing access to both antipodes of 2.
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■ Enantioselective Synthesis of 1S,3S,5S- and 1R,3S,5R-2-Azabicyclo[3.3.0]octane-3-carvoxylic Acid Starting from L-Serine
Hansjoerg Urbach* and Rainer Henning
*Entwicklungsgruppe Synthese und SBU Antiinfektiva, Allgemeine Pharma Forschung, Hoechst AG, Postfach 800320, D-65926 Frankfurt, Main 80, Germany
Abstract
(1S,3S,5S)- and (1R,3S,5R)-2-Azabicyclo[3.3.0]octane-3-carboxylic acid have been synthesized by intramolecular radical cyclysation of methyl 2-(S)-[N-benzyloxycarbonyl-N-(2-cyclopenten-1-yl)amino]-3-iodopropionate and subsequent reactions.
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■ Asymmetric Dithioacetals III: The Preparation of the Enantiomers of 3-(((3-(2-(7-Chloroquinolin-2-yl)-(E)-ethenyl)ohenyl)-3-dimethylamino-3-oxopropylthio)methyl)thio)propionic Acid (L-660,711) (MK-571), an Antagonist of Leukotriene D4
Robert N. Young,* Jacques Yves Gauthier, Michel Thérien, and Robert Zamboni
*Department of Medicinal Chemistry, Merck Frosst Centre for Therapeutic Research, P.O. Box 1005, Pointe-Claire-Dorval, Quebec, H9R 4P8, Canada
Abstract
The application of a novel method for the preparation of chiral dithioacetals to the synthesis of the enantiomers of L-660,711, an antagoinst of leukotriene D4, is described. Reaction of 3-(t-butylidiphenylisilyloxymethyl)-benzalehyde or isophthalaldehyde with (R)-(-)-α-methoxyphenylthiolacetic acid and N,N-dimethly-3-mercaptopropionamide provides diastereomeric acylthioalkylthioacetals (10,11 or 17a,b) which are readily separable and can be subsequently deacylated with sodium methoxide and the resultant thiolate anion alkylated with methyl acrylate to provide enantiomeric dithioacetals (12a,b or 14a,b) which are converted to the enantiomers of L-660,711.
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■ Oxidative Cyclization of 3-Anilinocyclohex-2-enones to Tetrahydrocarbazoles
Hans J. Schäfer* and Wolf Eilenberg
*Organisch-Chemisches Institut, Universität Münster, Orleansring 23, D-4400 Münster, Germany
Abstract
3-Anillno-cyclohex-2-enones 1a-1c are prepared from anilines and 5,5-dimethyl-1,3-cyclohexnedione. Anodic oxidation of 1a affords the p-benzoquinone monoimine dimethyl acetal 4, that is cyeilzed with CF3CO2H to the tetrahydrocarbazole 6. Lead tetraacetate oxidation of 1c leads directly to the tetrahydrocarbazole 9.
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■ Synthesis of 1-Hydroxy-7-azatricyclo[6.3.1.02.7]dodecan-9-ones: Potential Intermediates for the Total Synthesis of Securinines
Roland Côté, Pierre Bouchard, Yvon Couture, Roland Furstoss, Bernard Waegell, and Jean Lessard*
*Department of Chemistry, University of Sherbrooke, Sherbrooke, Quebec, J1K 2R1, Canada
Abstract
A synthesis of epimeric 1-hydroxy-7-azatricyclo [6.3.1.02.7]dodecan-9-ones (3 and 4), in ten steps from p-methoxyphenol, is described. They have been converted to the corresponding 9(10)-olefinic derivatives 22 and 23.
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■ Neisoposinine: A New Oxindole Alkaloid from Neisoperma oppositifolia [Apocynaceae]
A. A. Leslie Gunatilaka,* H. Chandasiri Fernando, Att-ur-Rahman,* M. Munawer Qureshi, and Sinnathamby Balasubramaniam
*Department of Chemistry, University of Peradeniya, Peradeniya, Sri Lanka
Abstract
A new oxindole alkaloid named neisosposinine was isolated from the stem bark of Neisosperma oppositifolia and its structure was elucidated as (1) with the aid of spectroscopic data. The C-18 methyl epimer of (1), isocarapnaubine (2) was also isolated along with three indole alkaloids, reserpiline (3), isoreserpiline (4) and ochroposinine (5).