Regular Issue

Vol. 53, No. 4, 2000

20 data found. 1 - 20 listed
Communication | Regular issue | Vol 53, No. 4, 2000, pp. 761 - 764
Published online:
DOI: 10.3987/COM-99-8806
Trapping of Unsaturated Fulvene Endoperoxides with Dimethyl 1,2,4,5-Tetrazine-3,6-dicarboxylate: A New Synthesis of Alkylidene- and Arylidenemalonaldehydes

Galip Özer, Nurullah Saraçoglu, and Metin Balci*

*Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey


Unsaturated fulvene endoperoxides (2a-e) were trapped with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate (4). The formed saturated fulvene endoperoxides containig 1,2-dihydropyridazine ring (6a-e) were characterised by spectroscopic methods. Treatment of (6a-e) with cobalt(II) tetraphenylporphyrin (CoTPP) provided alkylidene- and arylidenemalonaldehydes (9a-e).

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Communication | Regular issue | Vol 53, No. 4, 2000, pp. 765 - 770
Published online:
DOI: 10.3987/COM-99-8818
Convenient Synthesis of a 2,3,6-Tristhiazolylsubstituted Pyridine Skeleton [Fragment A-C] of a Macrocyclic Antibiotic, GE 2270 A

Kazuo Okumura, Taishi Suzuki, and Chung-gi Shin*

*Laboratory of Organic Chemistry, Faculty of Technology, Kanagawa University, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan


Convenient synthesis of the 2,3,6-tristhiazolylsubstituted pyridine skeleton [Fragment A-C] of a macrocyclic antibiotic, GE 2270 A, was first achieved from a chiral 2-(2-{2-[(1R,2S)-(1-amino-2-hydroxy-2-phenyl)ethyl]-thiazol-4-yl}thiazol-4-yl)pyridine derivative [Fragment A] and H-L-Ser-L-Pro-NH2 as the precursor of Fragment C.

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Communication | Regular issue | Vol 53, No. 4, 2000, pp. 771 - 775
Published online:
DOI: 10.3987/COM-00-8853
Asymmetric Syntheses of (+)-Camptothecin and (+)-7-Ethyl-10-methoxycamptothecin

Keiko Tagami, Norio Nakazawa, Shigeki Sano, and Yoshimitsu Nagao*

*Faculty of Pharmaceutical Sciences, The University of Tokushima, Sho-machi, Tokushima 770-8505, Japan


Total syntheses of (+)-camptothecin (1a) and (+)-7-ethyl-10-methoxycamptothecin (1b) from racemic ethyl 1-ethoxycarbonyl-3-oxopyrrolidin-2-ylacetate (7) were accomplished via asymmetric hydroxylation onto C20 of racemic 20-deoxycamptothecin derivatives (3a,b) employing a chiral Davis reagent, (2R, 8aS)-(+)-(camphorylsulfonyl)oxaziridine.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 777 - 784
Published online:
DOI: 10.3987/COM-99-8744
Total Syntheses of Kurasoins A and B, Novel Protein Farnesyltransferase Inhibitors, and Absolute Structures of Kurasoins A and B

Tomoyasu Hirose, Toshiaki Sunazuka, Tian Zhi-Ming, Masaki Handa, Ryuji Uchida, Kazuro Shiomi, Yoshihiro Harigaya, and Satoshi Omura*

*Research Center for Biological Function, The Kitasato Institute and School of Pharmaceutical Sciences, Kitasato University, Shirokane, Tokyo 108-8642, Japan


Asymmetric total syntheses of kurasoins A (1) and B (2), recently discovered protein farnesyltransferase (PFTase) inhibitors, have been achieved in seven steps from 2-(4-hydroxyphenyl)ethanol via the stereospecific alkylation of the chiral epoxide ((-)-7) and in four steps from phenylacetaldehyde via the coupling reaction of the chiral epoxide ((-)-13) with indole, respectively. The synthesis defined the (3S) absolute configuration of 1 and 2. The stereochemistry of the hydroxy group is important for eliciting PFTase inhibition.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 785 - 796
Published online:
DOI: 10.3987/COM-99-8788
Synthesis of New Spiro-N -heterocycles with Cyclooctane Fragment from N -(1-Alkenylcyclooctyl)-N -aryl(benzyl) Amines

Leonor Vargas M., Wilson Rozo, and Vladimir Kouznetsov*

*Laboratory of Fine Organic Synthesis, School of Chemistry, Industrial University of Santander, A.A. 678, Bucaramanga, Colombia


The homoallylic amines (6-10) derived from N-cyclooctylidenearyl (benzyl)amines and allyl- or prenylmagnesium bromides as organometallic reagents have been used for synthesis of spiro-N-heterocycles. The tetrahydrospiro[3H-2-benzazepine-3,1’-cyclooctanes] (11 and 12) have been obtained from the homoallylamines (6 and 7) under acidic conditions. The tetrahydro-1-benzazepine (15) spiroannulated with a cyclooctane moiety has been prepared by treating the homoallylic amine (9) with conc. sulfuric acid. Treatment of the homoallylmine (6) with 92% sulfuric acid in chloroform at reflux afforded tetrahydrospiro[1,2,3-oxathiazine-2,2-dioxide-4,1’-cyclooctane] (17). The latter has been converted into 1-benzyl-4-methylspiro[azetidine-2,1’-cyclooctane] (18). The homoallylamine (6) has been cyclized into the 1-benzylspiro[pyrrolidine-2,1’-cyclooctane] (19).

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 797 - 804
Published online:
DOI: 10.3987/COM-99-8814
Synthesis of 4-[4’-(N,N-Dimethylsulfamoyl)piperazin-1-yl]pyridine Derivatives as Sorbitol Dehydrogenase Potential Inhibitors

Didier Varlet, Eric Fourmaintraux, Patrick Depreux, and Daniel Lesieur*

*Institut de Chimie Pharmaceutiqe, Université de Lille 2, rue du Professeur Laguesse, 59006 Lille, France


A synthesis of various pyridines disubstituted in position 4 by a [4’-(N,N-dimethylsulfamoyl)piperazin-1-yl] group and in position 2 by different functionalities such as hydrogen, hydroxymethyl, formyl, carboxamido or cyano, is described.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 805 - 820
Published online:
DOI: 10.3987/COM-99-8819
A Synthesis and Transformations of Alkyl 2-[2-Cyano-2-(2-pyridinyl)ethenyl]amino-3-dimethylaminopropenoates. A One-Pot Synthesis of Pyrrolo[3,2-d ]pyrimidin-4-ones

Lucija Jukic, Jurij Svete, Amalija Golobic, Ljubo Golic, and Branko Stanovnik*

*Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, P.O. Box 537, 1000 Ljubljana, Slovenia


Alkyl 2-[2-cyano-2-(2-pyridinyl)ethenyl]amino-3-dimethylaminopro-penoates (8) and (9) were transformed by heating into alkyl 2-[2-cyano-2- (2-pyridinyl)ethenyl]amino-3-[2-methoxycabonyl-4-(2-pyridinyl)-1H-pyrrol-3-yl]aminopropenoates (12) and (13). Compounds (8) and (9) can be transformed in the presence of primary aliphatic amines into substituted pyrrolo[3,2-d]pyrimidines (17-19).

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 821 - 830
Published online:
DOI: 10.3987/COM-99-8820
Stereochemical Aspects during Addition Reaction of 2-Cyano-1,2-dihydroisoquinolines with Bromine in Methanol with and without Pyridine

Michiharu Sugiura,* Koosuke Asai, Keiichiro Hatano, Yukihisa Kurono, and Yoshiki Hamada

*Faculty of Pharmacy, Meijo University, Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan


2-Cyano-1-methoxy-1,2-dihydroisoquinoline (3) treated with bromine in methanol gave 4-bromo-2-cyano-1,3-dimethoxy-1,2,3,4-tetrahydroisoquinolines (4) exhibiting two configurational isomers (4a and 4b). During repeated recrystallization of 4a, auto-hydrolysis led it to 1-demethylation product (6), whereas 4b was intact giving single crystals. The structures of 4b and 6a were determined by X-Ray crystallography. 2-Cyano-1-hydroxy-1,2-dihydroisoquinoline (7) treated with bromine in methanol containing pyridine gave 6a stereoselectively in high yield, whereas from 3 compounds (4a) and (4b) were afforded in a product ratio of 1 : 1. The mechanisms for the 4a and 4b interconvertible reaction and also for the reaction from 7 to 6a were examined.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 831 - 839
Published online:
DOI: 10.3987/COM-99-8821
Dipolarophilic Behavior of the Isoxazole Ring in Intramolecular Nitrilimine Cycloadditions

Gianluigi Broggini, Luisa Garanti, Giorgio Molteni,* and Gaetano Zecchi

*Dipartimento di Chimica Organica e Industriale dell'Università and Centro CNR, Via Golgi 19, 20133, Milano, Italy


Upon base treatment with silver carbonate, isoxazolyl-substituted hydrazonoyl chlorides (4) and (12) undergo a sequential intra- intermolecular nitrilimine cycloaddition giving tetracyclic pyrazolydine derivatives (7) and (15).

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 841 - 850
Published online:
DOI: 10.3987/COM-99-8824
Electrochemical Synthesis of 2-Aryl-2H -benzotriazoles and Their N -Oxides by Controlled Potential Cathodic Electrolysis

Byeong Hyo Kim,* Doo Byung Lee, Dae Ho Kim, Rongbi Han, Young Moo Jun, and Woonphil Baik

*Department of Chemistry, Kwangwoon University, Seoul, 139-701, Korea


Using a divided cell, reductive cyclizations of o-nitrophenylazo dyes (1) toward 2-aryl-2H-benzotriazole-1-oxides (2) or 2-aryl-2H-benzotriazoles (3) were successfully accomplished by the controlled potential cathodic electrolysis reactions. 1 was transformed to 2 under neutral conditions while 1 was transformed to 3 under basic conditions.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 851 - 859
Published online:
DOI: 10.3987/COM-99-8825
Dioximes as Synthons for Medium Ring Heterocyclic Compounds

Maya Shankar Singh* and Ashwani Kumar Singh

*Department of Chemistry, D. D. U. Gorakhpur University, Gorakhpur-273 009 (U. P.), India


A simple and convenient synthetic approach to eight-, nine- and ten-membered nitrogen and oxygen containing heterocycles has been developed. 3,4-Diaryl-1,6,2,5-dioxadiazocines, (3) and (4), 3,4-diaryl-1,6,2,5-dioxadiazonines,(5) and 3,4-diaryl-1,6,2,5-dioxadiazacyclodeca-2,4-dienes (6) are prepared in one-pot from vicinal dioximes (1) via dianion intermediate (2) and 1,2-dibromoethylene, l,2-dichloroethane, 1,3-dibromopropane and 1,4-dichlorobutane, respectively. A plausible mechanism has bcen discussed.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 861 - 875
Published online:
DOI: 10.3987/COM-99-8826
1,3-Dipolar Cycloaddition between Hetaryl Nitrones and Methyl Acrylate: Theoretical Study and Application to the Synthesis of Functionalized Pyrrolidines

Pedro Merino,* Sonia Anoro, Francisco Merchan, and Tomas Tejero

*Departamento de Quimica Organica, Facultad de Ciencias, ICMA, Universidad de Zaragoza, E-50009 Zaragoza, Aragon, Spain


The 1,3-dipolar cycloaddition reaction of N-benzyl-C-(hetaryl)nitrones gave preferentially trans-substituted 3,5-disubstituted isoxazolidines (endo approach) which can be further converted into the corresponding 5-hetaryl-3-hydroxy-2-pyrrolidinones. A theoretical study of the cycloaddition reaction by using both semiempirical (AM1, PM3) and ab initio (HF/3-21G, HF/6-31G*//3-21G) methods has also been carried out. In all cases the obtained results are in good qualitative agreement with the experimental observations.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 877 - 886
Published online:
DOI: 10.3987/COM-99-8827
Mechanism on One-sided Wessely-Moser Rearrangement Reaction

Kazuki Shinomiya, Yoshio Hano, and Taro Nomura*

*Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan


Wessely-Moser rearrangement reaction of 5,7-dihydroxychromone derivatives with an isopentyl side chain at C-6 or C-8 position was examined. All reactions gave 8-isopentylchromone derivative predominantly as rearrangement product. Kinetic analysis of the one-sided rearrangement reaction revealed that the reaction depends on stability of a flavylium cation originated from 8-isopentylchromone derivative.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 887 - 896
Published online:
DOI: 10.3987/COM-99-8832
Stereoselective Synthesis of 1,4-Dideoxy-1,4-imino-L-lyxitol and 1,5-Dideoxy-1,5-imino-D-ribitol

Ki Chang Jang, Ill-Yun Jeong, Min Suk Yang, Sang Uk Choi, and Ki Hun Park*

*Department of Agricultural Chemistry, Gyeongsang National University, Chinju, 660-701, Korea


1,4-Dideoxy-1,4-imino-L-lyxitol (2) and 1,5-dideoxy-1,5-imino-D-ribitol (3) were prepared from allylic alcohol (1) derived from D-glucono-δ-lactone. Key transformation includes diastereoselective epoxidation of (1) with m-CPBA.

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 897 - 904
Published online:
DOI: 10.3987/COM-99-8834
Easy Access to Medium Rings by Entropy/Strain Reduction, Part 4. A Simple and Mild Route to Some Substituted 2,7-Dihydro-1H -oxepins, thiepins and a Phosphepin

James G. Walsh and Declan G. Gilheany*

*Department of Chemistry, National University of Ireland, Maynooth, Co. Kildare, Ireland


Reaction of substituted 1,6-dibromohexa-2,4-dienes (3) with sulfide ion leads to the corresponding dihydro-1H-thiepins (5) which were characterised as their sulfones 6. Reaction of 3 with dichlorophenylphosphine in the presence of sodium gives a low yield of dihydro-1H-phosphepin oxide (7). Reaction of the 1,6-diols (2) with butyllithium and p-toluenesulfonyl chloride gives the dihydro-1H-oxepins (8).

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Paper | Regular issue | Vol 53, No. 4, 2000, pp. 905 - 916
Published online:
DOI: 10.3987/COM-99-8837
Reactivity of Heterocyclic Enaminones: Regioselective Synthesis of Polyfused Indolones

Yves Blache,* Véronique Benezech, Jean-Michel Chezal, Pierre Boule, Henri Viols, Olivier Chavignon, Jean-Claude Teulade, and Jean-Pierre Chapat

*Laboratoire de Chimie Organique Pharmaceutique, E. A. 2414, 15 Avenue Charles Flahault, Faculté de Pharmacie, 34060 Montpellier, France


Photocyclization of heterocyclic enaminones to give partial hydrogenated derivatives of indolo[2,3-c]quinoline, pyrido[2,3-c]carbazole, and pyrido[4,3-a]carbazole is described. In addition, 3-[(5’-quinolinyl)- benzylamino]cyclohex-2-en-1-one and 3-[(8’-quinolinyl) benzylamino]cyclohex-2-en-1-one undergo C-N bond cleavages and a benzyl migration on the C-6 and C-7 positions respectively.

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Note | Regular issue | Vol 53, No. 4, 2000, pp. 917 - 927
Published online:
DOI: 10.3987/COM-99-8811
Nitrilimine Cycloadditions onto Partially Saturated Furo[3,4-c]thieno[2,3-d]pyrazoles. A Problem in Site Selectivity

Gianluigi Broggini, Luisa Garanti,* Giorgio Molteni, and Gaetano Zecchi

*Dipartimento di Chimica Organica e Industriale dell’Università and Centro CNR, Via Golgi 19, 20133 Milano, Italy


Partially saturated furo[3,4-c]thieno[2,3-d]pyrazoles (7-10) have been submitted to 1,3-dipolar cycloaddition with a variety of nitrilimines. The competitive formation of products due to the dipolar attack at different dipolarophilic sites has been observed. The experimental evidence is discussed by taking into account electronic features of the reactive species as well as their steric encumbrance.

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Note | Regular issue | Vol 53, No. 4, 2000, pp. 929 - 933
Published online:
DOI: 10.3987/COM-99-8830
A Novel and Convenient Synthesis of 1,3,5-Triazine-2,4(1H ,3H )-diones

Isao Shibuya,* Kazumasa Honda, Yasuo Gama, and Masao Shimizu

*National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan


Several 1,3,5-triazine-2,4(1H,3H)-diones (1-5) were newly synthesized by the reaction of N-substituted thiocarboamides with silver cyanate. The structure was confirmed by the X-Ray structure analysis, and the pathway affording them was estimated.

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Note | Regular issue | Vol 53, No. 4, 2000, pp. 935 - 940
Published online:
DOI: 10.3987/COM-00-8849
Synthesis of Heteromine C from Guanine

Erik Jakobsen and Lise-Lotte Gundersen*

*Department of Chemistry, University of Oslo, P.O.Box 1033, Blindern, N-0315 Oslo, Norway


Heteromine C previously isolated from a Taipei folk medicine plant, has been synthesised for the first time by selective methylation reactions starting from guanine. Thermal rearrangement to 1-methylherbipoline takes place when heteromine C is heated. It is shown that treatment of O6,9-dimethylguanine with methyl iodide gives the O6,7,9-trimethylguaninium iodide with complete selectivity, while similar reaction on O6,7-dimethylguanine results in methylation both in the 3- and 9-position.

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Review | Regular issue | Vol 53, No. 4, 2000, pp. 941 - 977
Published online:
DOI: 10.3987/REV-99-527
β-Halovinylaldehydes - As Versatile Reactive Intermediates in the Syntheses of Condensed Fused Ring Polycyclic Heterocycles

Batchu Chandra Sekhar,* Sukuru Raghu Ramadas, and Devella Venkata Ramana

*Department of Chemistry, Indian Institute of Technology, Chennai - 600 036, India


New approaches for the syntheses of a wide range of mono and polycyclic heterocycles utilizing β-halovinylaldehydes are summarized. The syntheses of a variety of heterocycles employing this synthon are discussed vividly in this review with 80 reference citations.

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20 data found. 1 - 20 listed