Regular Issue

Vol. 57, No. 8, 2002

16 data found. 1 - 16 listed
Communication | Regular issue | Vol 57, No. 8, 2002, pp. 1399 - 1402
Published online:
DOI: 10.3987/COM-02-9520
Asymmetric Epoxidation of Aldehydes Catalyzed by New C2-Symmetrical Chiral Sulfide

Miyuki Ishizaki* and Osamu Hoshino*

*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 12, Ichigaya Funagawara-machi, Shinjuku-ku, Tokyo 162-0826, Japan


Asymmetric synthesis of chiral epoxides from various aldehydes with benzyl bromide was investigated using new C2-symmetrical chiral sulfides, which were readily prepared from (R,R)-tartaric acid.

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Communication | Regular issue | Vol 57, No. 8, 2002, pp. 1403 - 1408
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DOI: 10.3987/COM-02-9526
Photochemical Synthesis of Naphthocyclobutapyrimidines via 1,2-Cycloaddition of 6-Chloro-1,3-dimethyluracil with Naphthalenes

Kazue Ohkura, Shun Uchiyama, Kazuya Aizawa, Ken-ichi Nishijima, and Koh-ichi Seki*

*Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan


UV-Irradiation of a solution of 6-chloro-1,3-dimethyluracil (6-ClDMU) and naphthalene in a non-polar solvent (cyclohexane) afforded 6-(1-naphthyluracil) as the sole product. In contrast, irradiation of a solution of 6-ClDMU and naphthalene in a polar medium in the absence of TFA effected 1,2-cycloaddition to give naphthocyclobutapyrimidines in moderate yields. This photocycloaddition reaction also proceeds in non-polar solvents in the presence of TFA.

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Communication | Regular issue | Vol 57, No. 8, 2002, pp. 1409 - 1412
Published online:
DOI: 10.3987/COM-02-9536
Facile Synthesis of [5.n.1.01,5]Tricycles Mediated by Intramolecular Pauson-Khand Reaction of 3-Alkynyl-1-alkylidenecyclic Compounds

Miyuki Ishizaki,* Mina Masamoto, and Osamu Hoshino*

*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 12, Ichigaya Funagawara-machi, Shinjuku-ku, Tokyo 162-0826, Japan


Intramolecular Pauson-Khand reaction of various 3-alkynyl-1-alkylidenecyclic compounds gave corresponding [5.n.1.01,5] tricyclic compounds (n = 2-4). Facile construction of core structure for total synthesis of cedrene-type terpenoid, cedranediol, was also investigated.

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Paper | Regular issue | Vol 57, No. 8, 2002, pp. 1413 - 1421
Published online:
DOI: 10.3987/COM-02-9499
Synthesis and NMR Structural Assignment of 3-Benzoylpyrrolo[2,3-b]quinoxalin-2(4H)-ones

Katarzyna Ostrowska,* Marek Zylewski, and Krzysztof Walocha

*Department of Organic Chemistry, Jagiellonian University, R.Ingardena 3, PL-30060 Kraków, Poland


A series of 3-benzoylpyrrolo[2,3-b]quinoxalin-2(4H)-ones, potential bioactive compounds have been synthesized. Their preparation is based on the efficient, regiospecific condensation of o-phenylenediamine with pyrrolidine-2,3,5-trione (1) or its enaminone derivatives, respectively, affording two polymorphic forms of the latter in solid. The NMR spectral assignment of 3-benzoylpyrrolo[2,3-b]quinoxalin-2(4H)-ones confirms the presence of only one isomer with enaminone moiety in solution.

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Paper | Regular issue | Vol 57, No. 8, 2002, pp. 1423 - 1432
Published online:
DOI: 10.3987/COM-02-9500
Microwave Assisted Synthesis of New Benzimidazoles

Yves Njoya, Narimène Boufatah, Armand Gellis, Pascal Rathelot, Michel P. Crozet, and Patrice Vanelle*

*Laboratoire de Chimie Organique, Faculté de Pharmacie, Université de la Méditerranée, 27, Boulevard Jean Moulin, 13385 Marseille Cedex 05, France


New potentially bioactive and highly functionalized benzimidazoles were synthesized by using microwave irradiation methodology in multi-steps: construction of benzimidazole ring, N-methylation and electron transfer C-alkylation (followed by base-promoted nitrous acid elimination) or S-alkylation.

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Paper | Regular issue | Vol 57, No. 8, 2002, pp. 1433 - 1444
Published online:
DOI: 10.3987/COM-02-9502
A Synthesis of Oxygenated 1-Azaanthraquinones via Diels-Alder Reaction of 2,4-Dioxygenated Quinoline-5,8-diones with 1-Methoxy-3-trimethylsilyloxy-1,3-butadiene

Yoshie Horiguchi,* Noriko Fukuda, Mutsumi Takada, and Takehiro Sano

*Showa Pharmaceutical University, 3-3165, Higashi-tamagawagakuen, Machida, Tokyo 194-8543, Japan


Diels-Alder reaction of 2,4-dioxygenated quinoline-5,8-diones (7a, b and 8) with 1-methoxy-3-trimethylsilyloxy- 1,3-butadieneÅ@(11) proceeded in a regio- and stereoselctive manner to give 2,4,6,8-tetraoxygenated 1-azaanthraquinoes (12a, b and 18) in good to moderate yields, respectively. The results demonstrated that Diels-Alder reaction of the 2,4-dioxygenated quinolone-5,8-diones with the activated diene provides a useful method for synthesizing highly oxygenated 1-azaanthraquinones.

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Paper | Regular issue | Vol 57, No. 8, 2002, pp. 1445 - 1459
Published online:
DOI: 10.3987/COM-02-9504
Reactions of α-Oxo Ketenes with Amides: Experimental Data and Semiempirical AM1 Molecular Orbital Calculations

Emin Saripinar,* Ilhan Ozer Ilhan, and Yunus Akçamur

*Department of Chemistry, Arts and Sciences Faculty, Erciyes University, TR-38039 Kayseri, Turkey


The thermal decomposition of 4-acyl substituted furan-2,3-diones (1a, b) leads to the α-oxo ketenes (2a, b) as an intermediate which undergoes nucleophilic addition reactions with amides. Some of α-N-acyl-oxo-amide derivatives (4a-h) obtained show keto-enol tautomerism. The reaction mechanism of ketene (R1) with formamide (R2) are calculated by AM1 method. Transition states (TS1 and TS2) were further confirmed by vibrational analysis and characterized by the corresponding imaginary vibration modes and frequencies. According to calculations, intermediate (IN) is in the planar zwitterion structure. The transition structure (TS2) has almost a planar structure. Analysis of the molecular orbitals indicates that the reaction is best described as pseudopericyclic.

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Paper | Regular issue | Vol 57, No. 8, 2002, pp. 1461 - 1470
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DOI: 10.3987/COM-02-9505
Controlled Synthesis of Electron Deficient Nitro-1H-benzotriazoles

Callum J. McHugh, Daniel R. Tackley, and Duncan Graham*

*Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, U.K.


Nitro-1H-benzotriazole derivatives containing electron withdrawing substitutents in the ortho and meta positions to the nitro group have been synthesized by the simple and direct nitration of the parent 1H-benzotriazoles. The route of nitration and assignment of isomerism in these compounds is proposed based upon high level density functional theory (DFT) calculations.

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Paper | Regular issue | Vol 57, No. 8, 2002, pp. 1471 - 1485
Published online:
DOI: 10.3987/COM-02-9508
New Synthetic Route to Tetracyclic Quinazolin-4(3H)-one Ring System

Pramod K. Mohanta and Kyongtae Kim*

*School of Chemistry and Molecular Engineering, Seoul National University, Shillim-Dong, San 56-1, Seoul 151-742, Korea


Reactions of dithiazoles (1a-e) and (9a-b) with 3,4-dimethoxy-phenethylamine (2) in CH2Cl2 at room temperature produce 3,4-dihydro-3-(3,4-dimethoxyphenethyl)-4-oxoquinazoline-2-carbonitriles (3a-d) and 4-hydroxy-4-phenyl-3,4-dihydroquinazoline-2-carbonitriles (10a-b), respectively. Compounds (3a-d) on treatment with TFAA/HCl at 120-130°C gave 3-(3,4-dimethoxy- phenethyl)quinazoline-2,4(1H,3H)-diones (5a-d) in excellent yields. Quinazolin-4(3H)-ones (3a-d), quinazoline-2,4(1H,3H)-diones (5a-d) and their thieno analogs (3e and 5e) as well as 4-hydroxy-3-(3,4-dimethoxyphenethyl)-4-phenyl-3,4-dihydroquinazoline-2-carbonitriles (10a-b) are cyclized in the presence of P2O5/POCl3 in xylene at 130°C to tetracyclic benzazepino[2,3-b]quinazolinones (8a-d), isoquino[1,2-b]quinazolinones (6a-d), thienopyrimidinones (6e and 8e) as well as isoquino[1,2-c]quinazoline-6-carbonitriles (11a-b), respectively, in good yields.

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Paper | Regular issue | Vol 57, No. 8, 2002, pp. 1487 - 1493
Published online:
DOI: 10.3987/COM-02-9516
Asymmetric Nucleophilic Addition Reactions of Aldehydes with Optically Active Dithioacetals and Their Application to Optically Active α-Hydroxy Ketone Synthesis

Hideo Taka, Ken-ichi Fujita,* Akihiro Oishi, and Yoichi Taguchi

*National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan


Optically active dithioacetals were prepared by the reaction of acetals with dithiol (1) having a chiral binaphthyl skeleton. Asymmetric addition reactions of various aldehydes with lithiated dithioacetals smoothly proceeded to provide the corresponding chiral alcohols (4) and (5) in fair diastereomeric excess. Moreover, preparation of optically pure α-hydroxy ketone by removal of the chiral auxiliary of 4a was achieved without racemization.

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Note | Regular issue | Vol 57, No. 8, 2002, pp. 1495 - 1500
Published online:
DOI: 10.3987/COM-02-9509
New Diterpenoid Alkaloid from Spiraea formosana

Tian-Shung Wu,* Chia-Chan Hwang, Ping-Chung Kuo, A. G. Damu, Cheng-Jen Chou, and Chieh-Fu Chen

*Department of Chemistry, Natioanl Cheng Kung University, Tainan, 70101, Taiwan, R.O.C.


Chemical investigation on the ethanol extract of stem of Spiraea formosana has resulted in the isolation of a new diterpenoid alkaloid, spiraeaine A (1), together with seven known compounds, bakuchiol (2), p-hydroxybenzalde- hyde (3) , nonadecyl ferulate (4), glutinol (5), β-sitosteryl glucoside (6), mixture of β-sitosterol (7) and stigmasterol (8). Their structures were determined by the spectral analyses and by comparison with the literature values.

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Note | Regular issue | Vol 57, No. 8, 2002, pp. 1501 - 1506
Published online:
DOI: 10.3987/COM-02-9525
Synthesis of 1,4-Benzodiazepine-2,5-dione Derivatives

Tong-Ing Ho,* Wen-Shiong Chen, Chi-Wei Hsu, Yeun-Min Tsai, and Jim-Min Fang

*Department of Chemistry, National Taiwan University, Roosevelt Road Section 4, Taipei 106, Taiwan, R.O.C.


A synthesis of a series of 1,4-benzodiazepine-2,5-dione derivatives with a carboxy group at the 3-position is realized in good yields by using methyl malonylchloride as a key reagent and intramolecular nucleophilic substitution as ring closure reaction.

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Note | Regular issue | Vol 57, No. 8, 2002, pp. 1507 - 1512
Published online:
DOI: 10.3987/COM-02-9527
Four Dimeric Stilbenes in Stem Lianas of Gnetum Africanum

Ibrahim Iliya, Toshiyuki Tanaka,* Munekazu Iinuma, Zulfiqar Ali, Miyuki Furasawa, Ken-ichi Nakaya, Nobuyasu Matsuura, and Makoto Ubukata

*Gifu Prefectrual Institute of Health and Environmental Sciences, 1-1 Nakafudogaoka, Kakamigahara, Gifu 504-0838, Japan


From the stem lianas of Gnetum africanum Welw., four new stilbenoid dimers (gneafricanins C, D, E and F) were isolated along with four known compounds. The structures were established by spectroscopic analyses and chemical evidence. In addition the antioxidant activities of the compounds were also investigated.

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Note | Regular issue | Vol 57, No. 8, 2002, pp. 1513 - 1524
Published online:
DOI: 10.3987/COM-02-9534
Synthesis of 2,2’,2”,2”’-(1,2- Ethanediylidene)tetrafuran and Diels-Alder Reaction with Dimethyl Acetylenedicarboxylate

Marc-Etienne Schwenter, Kurt Schenk, Rosario Scopelliti, and Pierre Vogel*

*Institute of Molecular and Biological Chemistry, Swiss Federal Institute of Technology, EPFL-BCH, CH-1015 Lausanne-Dorigny, Switzerland


A one step procedure has been found that converts 2,2’-methylenedifuran (1) into 2,2,’,2”,2”’-(1,2-ethanediylidene)tetrafuran (4: 1,1,2,2-tetrakis(furan-2-yl)ethane). This compound adopts two similar C2V-symmetrical conformations (4A and 4A’) in the crystalline state in which the C-H bond of the 1,2-ethanediylidene moieties is anti-periplanar with the C(2)-O bond of the vicinal furan-2-yl groups. Tetrafuran (4) is little reactive toward dienophiles with normal electronic demand. With dimethyl acetylenedicarboxylate a single 1:1 adduct (8) (dimethyl (1RS,2RS,2aRS,5SR,5aRS,6RS,8aRS,8bSR)-1,2-di(furan-2-yl)-1,2-dihydro-5H,6H-2a,5:6,8a-diepoxyacenaphthylene-5a,8b-dicarboxylate) was isolated. Its structure was established by single crystal X-Ray radiocrystallography.

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Review | Regular issue | Vol 57, No. 8, 2002, pp. 1525 - 1538
Published online:
DOI: 10.3987/REV-02-550
Synthetic Applications of Lewis Acid-Induced N-Methyleneamine Equivalents

Hyun-Joon Ha* and Won Koo Lee*

*Department of Chemistry, Hankuk University of Foreign Studies, Yongin, Kyunggi-Do, 449-791, Korea


The reactions involving one of the simplest imines, N-methyleneamine (monomeric formaldehyde imine), are very limited from the synthetic viewpoint because it is difficult to generate the N-methyleneamine. In this review are summarized a method and synthetic applications of N-methyleneamine equivalents generated from hexahydro-1,3,5-triazines or N-methoxymethylamines in the presence of a Lewis acid. Reactions with various nucleophiles yield aminomethylated products at the α-position of amines. Lewis acid-induced N-methyleneanilines can also serve as azadienes with electronrich diene for reverse electron demand [4π+2π] cycloaddition reactions.

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Review | Regular issue | Vol 57, No. 8, 2002, pp. 1539 - 1553
Published online:
DOI: 10.3987/REV-02-551
Polyhydroxylated Alkaloids with Lipophilic Moieties as Glycosidase Inhibitors from Higher Plants

Makio Shibano, Daisuke Tsukamoto, and Genjiro Kusano*

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


Two new types of polyhydroxylated alkaloids, broussonetines and radicamines, which have an aliphatic or an aromatic moiety, were isolated from Broussonetia kazinoki (Moraceae) and Lobelia chinensis (Campanulaceae), respectively, as glycosidase inhibitors. Feeding experiments using [1-13C] glucose and 13C-NMR spectroscopic studies showed that broussonetines are biosynthesized through routes similar to those of sphingosine and phytosphingosine.

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16 data found. 1 - 16 listed