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Regular & Special Issues

14 data found. 1 - 14 listed

Published online: 19th January, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13853
Syntheses of 4-Acetoxy- or Acetylthio-2-Substituted-Tetrahydrothiophene

Yaxi Li, Rui Ding, Yongguo Liu, Bianbian Ma, Baoguo Sun, and Hongyu Tian*

*Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University, Fucheng Road 11#, Haidian District 100048, China

Abstract

The generality of a three-step route for the preparation of 4-acetoxy-2-alkyltetrahydrothiophenes was investigated, which started from 1-alken-4-ols including epoxidation, mesylation and intramolecular nucleophilic substitution. 4-Acetoxy-2-alkyltetrahydrothiophenes could be produced in moderate to good yields by this method, even a bulky substituted group on the C-4 position of 1-alken-4-ol did not make significant effect on the reaction. In contrast, 1-alken-4-ols with an aryl group attached to the C-4 position gave acyclic products 1,4-diacetylthio-4-arylbutan-2-yl acetates when the reactions were carried out in acetonitrile under reflux. Whereas, 4-acetylthio-2-aryltetrahydrothiophenes were obtained in good yields when the reactions were carried out in toluene under reflux. A possible pathway for the latter involving an intermediate of episulfide was proposed

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Published online: 19th January, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13854
Coumarins with Anti-Melanogenesis Activities from a Chemically Engineered Extract of a Marine-Derived Fungus

Hitoshi Kamauchi, Kaoru Kinoshita, and Kiyotaka Koyama*

*Department of Pharmacognosy and Phytochemistry, Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan

Abstract

Chemical investigation of new resources is critical for developing medicinal leads. Chemically engineered extracts, a technique for derivatization of natural extracts, was performed on crude extracts of marine-derived fungus Eurotium rubrum; the resulting reaction mixture exhibited enhanced tyrosinase inhibition. Coumarin derivatives (1-3) were isolated from this chemically engineered extract. The structures of 1-3 were established using NMR, MS, and IR methods, revealing coumarin structures with side chains biosynthesized by the acetate-malonate pathway. 1-3 showed tyrosinase inhibition (IC50 = 7.7, 13.3, and 9.5 μM, respectively) and anti-melanogenesis activity (IC50 = 6.6, 7.2, and 6.6 μM, respectively, against B16 melanoma cells)

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Published online: 18th January, 2018

Review | Regular issue | Prepress
DOI: 10.3987/REV-17-875
Synthesis of Aza-Heterocycles and Related Molecules by Tf2NH-Catalyzed Cycloadditions

Naoya Shindo and Kiyosei Takasu*

*Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-machi, Sakyo-ku, Kyoto 606-8501, Japan

Abstract

Acid-catalyzed cycloadditions utilizing nitrogen-containing building blocks are powerful tools for the synthesis of azaheterocyclic molecules. This review summarizes Tf2NH-catalyzed cycloadditions of imines and other related building blocks with electron-rich alkenes, alkynes, and 1,3-dienes, giving a various type of azaheterocycles and related nitrogen-containing compounds

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Published online: 18th January, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13849
An Efficient Solvent- and Catalyst-Free Synthesis of Bicyclic Pyridones with High Molecular Diversity via Cascade Reaction

Huang-Mei Fu, Hong-Bin Wang, Li-Juan Yang, Wen-Rong Yang,* and Chao Huang*

*Engineering Research Center of Biopolymer Functional Materials of Yunnan, School of Chemistry and Environment, Yunnan Minzu University, Kunming 650500, China

Abstract

Two efficient cascade routes for synthesis of substituted bicyclic pyridines under solvent- and catalyst-free conditions have been developed. One is conducted by refluxing the reaction mixture of heterocyclic ketene aminals (HKAs), triethoxymethane and dicarbonyl compounds. The other one is proceeded with HKAs and diethyl ethoxymethylenemalonate (EMME) under ultrasound irradiation. Both routes for preparation of bicyclic 2-pyridones carried out with low cost and easy available substrates and achieved diversity of target compounds in good yields efficiently and environmental-friendly

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Published online: 17th January, 2018

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13847
Sulfanilic Acid-Catalyzed Green Synthesis of 4-Arylidene-2-Phenyl-5(4H)-Oxazolones

Hamzeh Kiyani* and Shiva Aslanpour

*School of Chemistry, Damghan University, 36719-41167 Damghan, Iran

Abstract

This study is focused on the catalytic activity of sulfanilic acid (SA) in the straightforward synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones via condensation of aromatic aldehydes, hippuric acid, and acetic anhydride under green experimental conditions (water solvent). The catalyst could be recovered easily from the filtrate via evaporation of the solvent and reused many times. It was found that the method is clean, relatively rapid, and environmentally friendliness alternative for the synthesis of Erlenmeyer-Plöchl azlactones as well as no needed for heating, microwave and ultrasound irradiations. Furthermore, all of the substrates and catalyst are easily accessible and inexpensive

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Published online: 15th January, 2018

Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13844
One-Pot Three-Component Synthesis of Novel Pyrazole-2,3-Pyrroledicarboxylic Acid 2,3-Diesters

Emi Shirouzu, Eiichi Masumoto, Fumi Okabe-Nakahara, Kenji Yamagata, and Hiroshi Maruoka*

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

Abstract

A facile synthesis of a series of pyrazol-3-one derivatives containing dihydropyrrole moiety using an efficient three-component reaction with 4-(dicyanomethylene)-3H-pyrazol-3-ones, acetylenic esters, and anilines is reported. The reaction is moderate to good yielding, tolerant towards a variety of amines, and provides access to novel pyrazole-2,3-pyrroledicarboxylic acid 2,3-diesters in a single step. All the synthesized compounds were characterized by spectroscopic analysis

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Published online: 9th January, 2018

Additions and Corrections | Regular issue | Prepress
DOI: 10.3987/Erratum-COM-17-13735
Errata Antiviral Activities of Some New 2,4,6-Trisubstituted 1,3,5-Triazines Having Alkoxy and/or Alkylamino Groups”: HETEROCYCLES, 2017, 94, 1653, DOI: 10.3987/COM-17-13735

Nobuko Mibu, Kazumi Yokomizo, Ai Yuzuriha, Marie Otsubo, Yuna Kawaguchi, Marina Sano, Izumi Sakai, Keita Nakayama, Jian-Rong Zhou, and Kunihiro Sumoto*

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

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Published online: 28th December, 2017

Communication | Special issue | Prepress
DOI: 10.3987/COM-17-S(T)7
Enantioselective Cycloadditions between Aliphatic Nitrile Oxides and 2-Hydroxystyrenes Catalyzed by Chiral Amine-Urea

Yasunori Toda, Masato Koyama, Hiroyoshi Esaki, Kazuaki Fukushima, and Hiroyuki Suga*

*Department of Materials Chemistry, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan

Abstract

Chiral amine-urea-catalyzed enantioselective 1,3-dipolar cycloadditions of nitrile oxides with 2-hydroxy-3-methoxystyrene are described. Aliphatic aldehyde-derived hydroximoyl chlorides were used as nitrile oxide precursors, providing optically active isoxazolines with moderate to good enantioselectivities.

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Published online: 26th December, 2017

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-17-S(T)8
Stereoinversion of a Tertiary Alcohol on a THP Ring: a Recovery Route to an Intermediate for Gymnocin-A

Takeo Sakai, Kayo Aoyama, Rie Oshima, Kyoko Furukawa, and Yuji Mori*

*Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan

Abstract

The stereoinversion of a tertiary alcohol on a tetrahydropyran ring was achieved through a five-step sequence including regioselective dehydration, diastereoselective epoxidation and reduction. This approach offers a recovery route from the diastereomer to the desired tertiary alcohol as part of the synthesis of gymnocin-A.

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Published online: 25th December, 2017

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-17-13840
Synthesis of 6,7-Dihydro-5H-thiopyrano[2,3-d]pyrimidin-5-one Derivatives Starting with 4,6-Dichloro-2-(methylsulfanyl)pyrimidine

Kazuhiro Kobayashi,* Ryoga Ono, Kouki Ishitobi, Ikuma Murayama, Hidetaka Hiyoshi, and Kazuto Umezu

*Applied Chemistry Field, Chemistry and Biotechnology Course, Department of Engineering, Graduate School of Sustainability Science, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan

Abstract

An efficient synthesis of 7-substituted 6,7-dihydro-5H-thiopyrano[2,3-d]pyrimidin-5-one derivatives from readily available 4,6-dichloro-2-(methylsulfanyl)pyrimidine (DCSMP) has been developed. Thus, this starting material is converted to the corresponding 1-(4-chloro-6-methoxy(or dialkylamino)pyrimidin-5-yl)alk-2-en-1-ones by using easily operational sequences. These enones are then treated with sodium hydrogensulfide under mild conditions to afford the desired products in satisfactory yields

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Published online: 19th December, 2017

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-17-S(T)6
Concise Approach to Mono- and Disubstituted Luotonin A Analogs and Their Cytotoxicity Test

Natsuko Kagawa,* Kimiko Nishimura, Shinya Abe, Takashi Masuko, and Masahiro Toyota*

*Department of Chemistry, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan

Abstract

A concise approach for the preparation of luotonin A analogs has been developed. The new synthetic route contains an anion-assisted intramolecular double hetero Diels ̶ Alder reaction and a direct oxidative cross coupling reaction. Some synthetic luotonin A analogs show cytotoxic activities against Daudi and Jurkat human cancer cells as potent as camptothecin.

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Published online: 18th December, 2017

Paper | Special issue | Prepress
DOI: 10.3987/COM-17-S(T)2
Synthesis of Substituted t-Butyl 3-Alkyl-oxindole-3-carboxylates from Di-t-Butyl (2-Nitrophenyl)malonates

Yusuke Yamai, Akio Tanaka, Tatsuo Yajima, Kyoji Ishida, Itaru Natsutani, Shinichi Uesato, Yasuo Nagaoka, and Takaaki Sumiyoshi*

*Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan

Abstract

Using a novel tandem reduction-cyclization, we synthesized t-butyl 3-alkyloxindole-3-carboxylates from the di-t-butyl 2-alkyl-2-(2-nitrophenyl)-malonate. Introduction of an α-substituent to the di-t-butyl 2-(2-nitrophenyl)-malonates and addition of acid promoted reactivity. This methodology was successfully applied to gram-scale-synthesis of the t-butyl 3-methyloxindole-3-carboxylate 1 and 3-hydroxymethyl-3-methyloxindole 2 without silica gel column chromatography.

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Published online: 17th November, 2017

Paper | Special issue | Prepress
DOI: 10.3987/COM-17-S(T)1
Asymmetric Total Synthesis and Structure Confirmation of (+)-(3E)-Isolaurefucin Methyl Ether

Te-ik Sohn, Byungsook Kim, Deukjoon Kim,* and Robert S. Paton

*The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Shillim-Dong, San 56-1, Kwanak-Gu, Seoul 151-742, Korea

Abstract

An asymmetric total synthesis and structure confirmation of (+)-(3E)-isolaurefucin methyl ether (2a) was accomplished. Our synthesis features two complementary routes to construct the α,α’-trans-2,8- dioxabicyclo[5.2.1]decane skeleton of the natural product from α,α’-trans-γ,δ-unsaturated oxocene alcohol 7, namely, an intramolecular epoxide opening route and a novel methoxyetherification route based on organoselenium- mediated oxonium ion formation/fragmentation. A computational analysis was performed to model the observed different fragmentation behaviors of the respective oxonium ions 8 and 8’ derived from α,α’-trans- and α,α’-cis-γ,δ-unsaturated oxocene alcohols 7 and 7’ during the organoselenium-mediated oxonium ion formation/fragmentation. Regarding the possibility of the natural product being an artifact, the reactivity of chlorofucin surrogate 16 and neoprelaurefucin surrogate 16’ during methanolysis was compared, the results were in good agreement with calculations.

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Published online: 17th November, 2017

Paper | Special issue | Prepress
DOI: 10.3987/COM-17-S(T)3
Polymeric Silver(I) Complexes Based on Bidentate Imidazoline-2-thiones Synthesis and Crystal Structures

Barbara Rietzler, Gerhard Laus, Klaus Wurst, Thomas Gelbrich, Sven Nerdinger,* Erwin Schreiner, and Herwig Schottenberger

*Sandoz GmbH, Biochemiestrasse 10, 6250 Kundl, Austria

Abstract

The bidentate ligand 1,6-bis(1-methylimidazol-2-ylthio)hexane or its hexafluoride salt reacted with silver(I) triflate, nitrate or oxide, respectively, to give the corresponding polymeric silver(I) complexes. Three crystal structures have been determined and showed linear and cyclic motifs.

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14 data found. 1 - 14 listed