Special Issue

Victor Snieckus's Special Issues, Vol. 88, No. 1, 2014

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 417 - 424
Published online: 17th July, 2013
DOI: 10.3987/COM-13-S(S)42
Synthesis and Molecular Structure of Cyclo[8](9,10-dihydro-9,10-anthraceno)pyrrole

Tetsuo Okujima,* Chie Ando, Shigeki Mori, Takahiro Nakae, Hiroko Yamada, and Hidemitsu Uno

*Department of Chemistry and Biology, Graduate School or Science and Engineering, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan

Abstract

Cyclo[8]pyrrole with eight 9,10-dihydroanthracene wings was synthesized by oxidative coupling of the corresponding 2,2'-bipyrrole in good yield. The molecular structure was determined by single crystal X-ray analysis. The three-dimensionally structured cyclo[8]pyrrole possessed a cavity created by a pair of slip-stacked cyclo[8]pyrroles.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 425 - 440
Published online: 2nd August, 2013
DOI: 10.3987/COM-13-S(S)46
Synthesis of Tetrahydroquinolines through Intramolecular Carbolithiation Reactions

Oihane García-Calvo, Unai Martínez-Estíbalez, Esther Lete, and Nuria Sotomayor*

*Departamento de Química Orgánica, Facultad de Ciencia y Tecnologia, Universidad del País Vasco, Barrio Sarriena s/n. Leioa (Bizkaia) Bilbao 48940, Spain

Abstract

Cyclization of aryllithiums obtained by iodine-lithium exchange reaction on N-alkenyl 2-iodoanilines allows the synthesis of 4- and 2,4-substituted tetrahydroquinolines. However, the alkene has to be substituted with a stabilizing group for the resulting organolithium to favor the intramolecular carbolithiation. When (–)-sparteine (4) or (+)-sparteine surrogate (5) are used as chiral ligands low levels of enantioselection are obtained. The carbolithiation is completely diastereoselective when an enantiomerically pure precursor is used.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 441 - 452
Published online: 23rd July, 2013
DOI: 10.3987/COM-13-S(S)50
Highly Efficient, Enantiocontrolled Total Syntheses of (+)-Heliannuol D and (–)-Helibisabonol A

Yuki Manabe, Makoto Kanematsu, Mayu Osaka, Masahiro Yoshida, and Kozo Shishido*

*Graduate School of Pharmaceutical Sciences, University of Tokushima, 1-78-1 Sho-machi, Tokushima 770-8505, Japan

Abstract

Enantiocontrolled total syntheses of (+)-heliannuol D (1) and ()-helibisabonol A (2) have been accomplished efficiently from a common intermediate 9, derived from the optically pure aryl allyl ether 7 via a chirality transfer through a Lewis acid-mediated Claisen rearrangement and asymmetric dihydroxylation.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 453 - 462
Published online: 29th July, 2013
DOI: 10.3987/COM-13-S(S)53
Study on Hinsberg Thiophene Synthesis of 4,8-Dihydro-4,8-ethanobenzo[1,2-c;4,5-c’]dithiophene

Kazunari Tagawa, Shigeki Mori, Takahiro Nakae, Tetsuo Okujima, and Hidemitsu Uno*

*Department of Chemistry and Biology, Graduate School or Science and Engineering, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan

Abstract

The Hinsberg thiophene synthesis using 4,5,6,7-tetrahydro-4,7-ethanothiophene-5,6-dione and diethyl thiodiglycolate afforded a mixture of diethyl 4,8-dihydro-4,8-ethanobenzo[1,2-c;4,5-c’]dithiophene-1,3-dicarboxylate and its dihydrate, although the yields were low. The latter dihydrate was converted to the former dithiophene in a good yield by the treatment with Ac2O and DMAP.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 463 - 474
Published online: 14th August, 2013
DOI: 10.3987/COM-13-S(S)59
Synthesis of Novel Benzofuran Fused 1-Azaazulene Derivative by Tandem Intermolecular Suzuki Coupling/Intramolecular Buchwald-Hartwig Type Coupling

Hiroyuki Fujii,* Kazuya Sanada, Yu Kawai, Reiko Ikeda, Takeo Konakahara, and Noritaka Abe

*Department of Chemistry, Faculty of Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8512, Japan

Abstract

Synthesis of benzofuran fused 1-azaazulene derivative (cyclohepta[d]benzo[4,5]furano[2,3-b]pyrrole) (4) was achieved successfully by tandem intermolecular Suzuki coupling/intramolecular Buchwald-Hartwig type coupling of 2-chloro-3-iodo-1-azaazulene with 2-hydroxyphenylboronic acid pinacolate in the presence of Pd catalyst. The compound 4 was also obtained by the reaction of 2-chloro-1-azaazulene with 2-iodophenol in the presence of Pd catalyst in one pot. It was considered that the obtained tetra-cyclic heterocycles would consist 18π peripheral conjugated system by the studies of UV/Vis spectra and 1H NMR spectra, together with DFT calculation.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 475 - 491
Published online: 23rd July, 2013
DOI: 10.3987/COM-13-S(S)60
Enantioselective Synthesis of Spirooxindoles via Direct Catalytic Asymmetric Aldol-Type Reaction of Isothiocyanato Oxindoles

Shota Kato, Motomu Kanai, and Shigeki Matsunaga*

*Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

Abstract

Direct catalytic asymmetric aldol-type reaction of aldehydes with isothiocyanato oxindoles is described. A dinuclear (S)-Ni2-Schiff base complex (0.1-10 mol %) efficiently catalyzed the addition of isothiocyanato oxindoles to aliphatic aldehydes, giving spirooxindole products in 80-99% ee and 81:19-91:9 dr. A Sr(O-iPr)2/Schiff base complex (10 mol %) was utilized for aryl aldehydes and spirooxindole products were obtained in 33-78% ee and 96:4-98:2 dr.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 493 - 520
Published online: 29th July, 2013
DOI: 10.3987/COM-13-S(S)74
Synthesis of 4-Amino-, 4-Hydroxy-, and 4-Nitro-1,3,4,5-tetrahydrobenz[cd]indols and Its Bromination

Kyoko Nakagawa, Naokatsu Aoki, Harunobu Mukaiyama, and Masanori Somei*

*Noto Marine Laboratory, Institute of Nature and Environmental Technology, Faculty of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, 56-7 Matsuhidai, Matsudo-shi, Chiba 270-2214, Japan

Abstract

Simple synthetic method for 4-nitro-1,3,4,5-tetrahydrobenz[cd]indole (6) is established from indole-3-carboxaldehyde (7). With 6 in hand, various derivatives of 4-amino-, 4-hydroxy- and 4-amino-4-hydroxymethyl-1,3,4,5-tetrahydrobenz[cd]indoles become readily available. Bromination of 6 afforded useful building blocks for further manipulation. Successful optical resolution of 6 by chiral column chromatography is also reported.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 521 - 534
Published online: 7th August, 2013
DOI: 10.3987/COM-13-S(S)76
A Thermal Potential [6+4] 2H-Transfer Reaction in a Cyclic Dimer of Dimethyl 2a,8a-Dihydrocyclopent[c,d]azulene-1,2-dicarboxylate

Peter Uebelhart, Erja Lehto, and Hans-Jürgen Hansen*

*Institute of Organic Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland

Abstract

Azulenes and dimethyl acetylenedicarboxylate (ADM) react under catalysis of diethylaluminum chloride (Et2AlCl) in toluene to corresponding 2a,8a-dihydrocyclopenta[cd]azulene-1,2-dicarboxylates, which on further influence of Et2AlCl dimerize by bond formation between the central C(8b) and C(8’b) atoms and inter alia C(3) and C(8’) atoms. The thus formed heptacyclic compounds undergo on heating in tetralin an intramolecular disproportionation by transfer of two H-atoms from one to the other part of the heptacyclic structures. The kinetics of this process is studied with partially deuterated heptacycles.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 535 - 546
Published online: 5th August, 2013
DOI: 10.3987/COM-13-S(S)77
Potential DNA Bis-Intercalating Agents. Synthesis and Antitumor Activity of N,N'-(Methylenedi-4,1-cyclohexanediyl-bis(9-acridinamine) Isomers

Gordon W. Gribble,* Michael D. Mosher, Gary D. Jaycox, Michael Cory, and Terri A. Fairley

*6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, U.S.A.

Abstract

We describe the synthesis and antitumor activity of three novel isomeric bis-acridines 14-16 possessing a non-aromatic, semi-rigid dicyclohexylmethylene tether.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 547 - 557
Published online: 30th July, 2013
DOI: 10.3987/COM-13-S(S)78
Preparation and Spectroscopic Study of Alternate meta-Ethynylpyridine Oligomer Involving 2,4,6-Trisubstituted and 3,5-Disubstituted Pyridine Rings

Hajime Abe,* Daiki Suzuki, Ayako Shimizu, and Masahiko Inouye*

*Graduate School of Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan

Abstract

A new type of ethynylpyridine cooligomer which consists of 3,5- and 2,6-pyridylene units alternately linked with acetylene bonds was prepared by repeating Sonogashira reaction. 1H NMR study suggested that this cooligomer associates with methanol by hydrogen-bonding at the pyridine units. Intramolecular excimer emission was observed around 540 nm by fluorescence measurement, indicating the formation of helical conformation. Weak induced CD was observed by the addition of octyl glucoside as a guest.

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Paper | Special issue | Vol 88, No. 1, 2014, pp. 559 - 590
Published online: 30th July, 2013
DOI: 10.3987/COM-13-S(S)82
Asymmetric Construction of Quaternary Stereogenic Centers via Auxiliary-Based SN2’ Reactions: A Case of 1,7-Relative Stereogenesis

Scott E. Denmark* and Lyndon K. Marble

*245 Roger Adams Laboratory Box 18-5 , Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, U.S.A.

Abstract

The stereoselective construction of quaternary stereogenic centers is described that employs an allylic substitution through the intermediacy of a chiral carbamate leaving group. Five carbamates with two substituents at the allylic terminus combined with phenylcopper or n-butylcopper to provide alkenes in moderate to good yields and with moderate to high enantioselectivities at the newly created quaternary stereogenic center. The E-carbamate with methyl and cyclohexyl substituents at the γ-terminus provided the highest yield (87%) and enantioselectivity (>99.9:0.1 er) of all the substitution patterns tested. The corresponding Z-carbamate gave the lowest enantioselectivity observed (80.0:20.0). Carbamates with other substituents (n-butyl and t-butyl) at the E-terminal position gave moderate yields and enantioselectivities of alkenes. Cinnamyl substrates also provided good yields of alkenes with moderate enantioselectivities. The origin of enantioselectivity is analyzed in the context of dimeric lithioheterocuprate structures.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 591 - 594
Published online: 18th April, 2013
DOI: 10.3987/COM-13-S(S)3
Aaptoline A, a New Quinoline Alkaloid from the Marine Sponge Aaptos suberitoides

Yodai Kudo, Hikaru Kato, Henki Rotinsulu, Fitje Losung, Remy E. P. Mangindaan, Nicole J. de Voogd, and Sachiko Tsukamoto*

*Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-hon-machi, Kumamoto 862-0973, Japan

Abstract

A new quinoline alkaloid, aaptoline A (1), was isolated from the marine sponge Aaptos suberitoides, along with known alkaloids, aaptamine (2), isoaaptamine (3), and demethylaaptamine (4). Interestingly, 1-4 are presumably biosynthesized from common precursors, L-DOPA and β-alanine aldehyde.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 595 - 602
Published online: 30th May, 2013
DOI: 10.3987/COM-13-S(S)4
Copper-Mediated Regioselective Homocoupling of Thiophenes and Indoles via Directed C–H Cleavage

Riko Odani, Mayuko Nishino, Koji Hirano,* Tetsuya Satoh, and Masahiro Miura*

*Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 560-0871, Japan

Abstract

We have developed a copper-mediated regioselective homocoupling reaction of thiophenes and indoles via functional-group-directed C–H cleavage to afford the corresponding bisthiophenes (bithiophenes) and bisindoles directly. The copper-based system can provide a concise and precious-metal-free access to the above heterocyclic cores of fundamental importance in material and pharmaceutical chemistry.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 603 - 606
Published online: 11th June, 2013
DOI: 10.3987/COM-13-S(S)7
Lewis Acid-Catalyzed Formylation Reaction of 4-(Piperazin-1-yl)phenols

Giuseppe Cremonesi, Piero Dalla Croce,* and Concetta La Rosa

*DISFARM - Section of General and Organic Chemistry "A. Marchesini", University of Milano, Via Venezian 21, I-20133 Milano, Italy

Abstract

The Lewis acid-catalyzed reaction of phenols 1 with paraformaldehyde in aprotic solvents affords good yields of salicylaldehydes 2.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 607 - 612
Published online: 24th May, 2013
DOI: 10.3987/COM-13-S(S)8
Two-Step Synthesis of 3,4-Ethylenedioxythiophene (EDOT) from 2,3-Butanedione

Iwao Hachiya, Toshihiro Yamamoto, Tatsuhiko Inagaki, Tomohiro Matsumoto, Atsushi Takahashi, Isao Mizota, and Makoto Shimizu*

*Department of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho Tsu, Mie 514-8507, Japan

Abstract

3,4-Ethylenedioxythiophene (EDOT) was synthesized from commercially available 2,3-butanedione in only a two-step procedure including ketalization and thiophene formation.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 613 - 620
Published online: 13th June, 2013
DOI: 10.3987/COM-13-S(S)9
Immobilisation of Phenanthroline-Bis Triazine (C1-BTPhen) on Magnetic Nanoparticles for Co-Extraction of Americium(III) and Europium(III)

Ashfaq Afsar, Dominic L. Laventine, Laurence M. Harwood,* Michael J. Hudson, and Andreas Geist

*Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K.

Abstract

The present work reports a convenient route for the immobilisation of a phenanthroline-bis triazine (C1-BTPhen) group on the surface of zirconia-coated maghemite (γ-Fe2O3) magnetic nanoparticles. The magnetic nanoparticles functionalized with C1-BTPhen were able to co-extract Am(III) and Eu(III) from nitric acid (HNO3). The extraction efficiency of these C1-BTPhen-functionalized magnetic nanoparticles for both Am(III) and Eu(III) was 20% at 4M HNO3. The interaction between C1-BTPhen and metal cations is reversible. These functionalized magnetic nanoparticles can be used for the co-extraction of traces of Am(III) and Eu(III).

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 621 - 628
Published online: 5th June, 2013
DOI: 10.3987/COM-13-S(S)10
Regioselectivity of the Intramolecular Biaryl Coupling Reaction of 3-Substituted Phenyl 2-Iodobenzoate using a Palladium Reagent

Kazuhiro Maeda, Takuya Matsukihira, Shumpei Saga, Yasuo Takeuchi,* Takashi Harayama, Yoshikazu Horino, and Hitoshi Abe*

*Department of Environmental Applied Chemistry, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930-8555, Japan

Abstract

This study investigated the regioselectivity of the intramolecular biaryl coupling reaction of the phenyl benzoate derivative which possesses a methyl or methoxy group at the meta-position of the phenoxy moiety. The type of base and the presence/absence of the phosphine ligand influenced the product ratio. A transition state model and the regioselectivity of the reaction are discussed.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 629 - 637
Published online: 12th June, 2013
DOI: 10.3987/COM-13-S(S)14
Synthesis of Methoxy-Substituted Diazirinyl Phenylalanine – A Novel Photoreactive Aspartame Derivative for Functional Analysis of Sweet Receptors

Munenori Sakurai, Katsuyoshi Masuda, Lei Wang, Yuta Murai, Yasuko Sakihama, Yasuyuki Hashidoko, Yasumaru Hatanaka, and Makoto Hashimoto*

*Division of Applied Science, Graduate School of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan

Abstract

Photoreactive phenylalanine derivatives are well known as functional analysis reagents for target biomolecules. The photophores are commonly introduced at 4-position on benzene. Aspartame, which consists of dipeptide L-Asp-L-Phe-OMe, is one of the most utilized artificial sweeteners, and substitution effects on its benzene ring have been reported. Substitution at the 4-position, however, does not maintain its sweetness properties. Trifluoromethyldiazirine, which is one of the most reliable photophores, was introduced to a different site on phenylalanine and the new photoreactive phenylalanine was converted to aspartame derivatives. The new aspartame derivative had slightly higher sweetness potency than sucrose standard solution.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 639 - 650
Published online: 1st July, 2013
DOI: 10.3987/COM-13-S(S)18
Expedient Synthesis of 2-Oxopiperazines Using a SN2 / Cope-Type Hydroamination Sequence

Nicolas Das Neves, Michaël Raymond, and André M. Beauchemin*

*Department of Chemistry, University of Ottawa, Ottawa Ontario, K1N 6N5, Canada

Abstract

An approach for the synthesis of 2-oxopiperazines from allylic 2-iodoacetamides and aqueous NH2OH has been developed. The reaction proceeds through a SN2 / intramolecular Cope-type hydroamination sequence yielding in 2-oxopiperazines with moderate to good yield.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 651 - 662
Published online: 25th June, 2013
DOI: 10.3987/COM-13-S(S)19
Synthesis of Oxygen-Bridged Decahydroazulene Derivatives: Simplified Analogues of Biologically Active Natural Products

Hideki Abe, Akira Tezuka, Toyoharu Kobayashi, and Hisanaka Ito*

*School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

Decahydroazulene derivatives having an ether bridge were synthesized. They are structurally simplified analogues of the biologically active guaiane sesquiterpenes englerin A and orientalol F.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 663 - 673
Published online: 21st June, 2013
DOI: 10.3987/COM-13-S(S)20
Synthesis of 4-Arylpiperidin-4-ol Derivatives of Loperamide as Agents with Potent Antiproliferative Effects against HCT-116 and HL-60 Cells

Noriyuki Hatae,* Tomoyuki Nagayama, Hiroyoshi Esaki, Eiko Kujime, Masabumi Minami, Minoru Ishikura, Tominari Choshi, Satoshi Hibino, Chiaki Okada, Eiko Toyota, Hideko Nagasawa, and Tatsunori Iwamura*

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

Abstract

The structure of 4-arylpiperidin-4-ol, a constituent of the antidiarrheal loperamide, is key to μ opioid receptor activation. Some opioid derivatives were recently reported to induce tumor cell death, but the chemical structures responsible for their antitumor activity remain unclear. We synthesized loperamide analogs and tested their antiproliferative activity against HCT-116 colon tumor cells and HL-60 leukemia cells. The N-substituents on 4-arylpiperidin-4-ol units were found to play an important role in their antiproliferative activity, and the N-diphenylpropanol analogs exhibited the most potent antiproliferative activity. Furthermore, the N-diphenylpropanol analog activated caspase-3, as was found previously for opioids that exhibited antitumor effects.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 675 - 687
Published online: 2nd July, 2013
DOI: 10.3987/COM-13-S(S)21
An Approach to the Synthesis of Novel Dihydroindoles Bearing Electron-Withdrawing Groups at C-2 Position

Fumi Okabe, Hiroshi Maruoka,* Masaru Takasu, Eiichi Masumoto, Toshihiro Fujioka, and Kenji Yamagata

*Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan

Abstract

The synthesis of novel dihydroindoles 8ad and 9ad bearing electron-withdrawing groups at C-2 position is presented. The key step of this approach is an efficient intramolecular Diels-Alder reaction of N-alkenylated 2-amino-3-furancarbonitriles 4ad and 5ad.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 689 - 704
Published online: 24th July, 2013
DOI: 10.3987/COM-13-S(S)23
Synthetic Studies on Glycosphingolipids from Protostomia Phyla: Synthesis of Glycosphingolipid from the Marine Sponge Spheciospongia vesparia and Its Analogue

Noriyasu Hada, Akira Miyamura, Isao Ohtsuka, and Fumiyuki Kiuchi*

*Faculty of Pharmacy, Keio University, 1-5-30 Shiba-Kouen, Minato-ku, Tokyo, Japan

Abstract

Stereocontrolled syntheses of a neutral glycosphingolipid found from a marine sponge Spheciospongia vesparia and its analogue have been accomplished. Disaccharide glycosphingolipids, β-D-Arap-(16)-β-D-Glcp-(11)-Cer (1) and α-D-Arap-(16)-β-D-Glcp-(11)-Cer (2), were synthesized from suitable monosaccharide donors and an acceptor by stepwise synthesis.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 705 - 710
Published online: 8th July, 2013
DOI: 10.3987/COM-13-S(S)25
Two-Directional Synthesis of 2,6-Dimethylpyrrolo[2,3-f]indole-4,8-dione by Double Claisen Rearrangement and Nitrene Cyclization

Andrea Visconti and Christopher J. Moody*

*School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.

Abstract

Double Claisen rearrangement of the bis-allyl ether of 2,5-dichloro-1,4-hydroquinone, followed by alkene isomerization, oxidation and double chloride displacement with azide gives 2,5-diazido-3,6-dipropenyl-1,4-benzoquinone. Upon heating, a double nitrene cyclization occurs completing a high yielding, two-directional route to the pyrrolo[2,3-f]indole-4,8-dione ring system.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 711 - 718
Published online: 2nd August, 2013
DOI: 10.3987/COM-13-S(S)26
One New Megastigmane Glycoside with a Double Bond at a Rare Position from the Leaves of Antidesma pentandrum var. barbatum

Ayumi Iha, Sachiko Sugimoto, Katsuyoshi Matsunami, Hideaki Otsuka,* and Yoshio Takeda

*Divison of Medicinal Chemisry, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan

Abstract

From the 1-BuOH-soluble fraction of a MeOH extract of leaves of Anitdesma pentandrum var. barbatum, one new megastigmane glycoside, α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside of (6ξ,9R)-megastigman-4(13)-en-9-ol, was isolated along with four known megastigmane glycosides, (6R,9R)-megastigma-4,7-dien-9-ol-3-one α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside, foliasalacinoside B, (6S,9R)-magastigma-4,7-diene-6,9-diol-3-one 9-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside and byzantionoside B.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 719 - 730
Published online: 16th July, 2013
DOI: 10.3987/COM-13-S(S)34
Synthesis of the Diazepanone-Nucleoside Core Structure of Liposidomycins and Caprazamycins Based on 7-Exo Cyclization of Epoxyamine

Hiroaki Miyaoka,* Jumpei Wada, and Etsuko Kawashima

*School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

The diazepanone-nucleoside core structure of liposidomycins and caprazamycins has been synthesized based on 7-exo cyclization of epoxyamine.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 731 - 740
Published online: 31st July, 2013
DOI: 10.3987/COM-13-S(S)35
Synthesis of Alkyl 3-Chloroazetidine-3-carboxylates via Regioselective Ring Transformation of Alkyl 2-(Bromomethyl)aziridine-2-carboxylates

Asta Žukauskaitė, Sven Mangelinckx, Algirdas Šačkus, and Norbert De Kimpe*

*Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium

Abstract

The synthesis of alkyl 3-chloroazetidine-3-carboxylates was developed by ring transformation of alkyl 2-(bromomethyl)aziridine-2-carboxylates utilizing ring opening with hydrochloric acid at the more sterically hindered carbon atom of the aziridine ring and subsequent base-promoted ring closure.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 741 - 753
Published online: 8th August, 2013
DOI: 10.3987/COM-13-S(S)36
Synthesis of Novel 5-Aryl/Hetarylidenyl 3-(2-Methyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-yl)-2-thioxothiazolidin-4-ones

Kimberly Mendoza, Sukanta Kamila, and Edward R. Biehl*

*Chemistry Department, Southern Methodist University, Dallas, TX 75275-0314, U.S.A.

Abstract

The synthesis of a variety of novel 5-substituted titled compounds containing a priviledged rhodanine scaffold is described. The synthesis involves a microwave (MW) assisted Knoevenagel condensation of 3-(2-methyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-yl)-2-thioxothiazolidin-4-one with suitably substituted aromatic aldehydes. However, these condensations fail with aliphatic aldehydes. The 2-thioxothiazolidin-4-one (rhodanine) precursor was prepared by the condensation of 2-thioxothiazolidin-4-one-di-(carboxymethyl)trithiocarbonyl and 4,5,6,7-tetrahydrobenzo[4,5]thienyl[2,3-d]- 2-methylpyrimidin-4-amine in the presence of K2CO3.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 755 - 763
Published online: 29th July, 2013
DOI: 10.3987/COM-13-S(S)38
Synthesis of 8-Amino-(dihydrofuran-Fused Perhydrophenanthrene) via Copper-Mediated Amination Reaction

Kenji Sugimoto, Kosuke Tamura, Naoki Toyooka, and Yuji Matsuya*

*Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan

Abstract

Introduction of nitrogen substituents on a highly functionalized dihydrofuran-fused perhydrophenanthrene (DF) core was examined. Acetamide functionality could be introduced on the DF by copper-mediated Buchwald-type coupling. On the other hand, installation of free amino group on a DF was established via an aryl azide under the copper-mediated condition reported by Helquist and co-workers.

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Short Paper | Special issue | Vol 88, No. 1, 2014, pp. 765 - 777
Published online: 31st July, 2013
DOI: 10.3987/COM-13-S(S)39
Regio- and Stereoselective Derivatisation of an Aporphine Scaffold

Jonathan D. M. Atkinson, Stephen G. Davies,* and James E. Thomson

*Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K.

Abstract

Treatment of 10,11-dimethoxyaporphine with chromium hexacarbonyl was found to give two diastereoisomeric products on regioselective co-ordination of the chromium tricarbonyl fragment to the A ring. For one of the diastereoisomeric complexes, alkylation was found to proceed with high regio- and diastereoselectivity at C(4), whereas regio- and diastereoselective alkylation was observed at C(6a) for the other diastereoisomer. In the case of the C(4)- and C(6a)-methylated products, these substrates were decomplexed in high yield to give the corresponding enantiopure, C(4)- and C(6a)-methyl substituted aporphines.

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