Regular Issue

Vol. 57, No. 2, 2002

18 data found. 1 - 18 listed
Communication | Regular issue | Vol 57, No. 2, 2002, pp. 219 - 222
Published online:
DOI: 10.3987/COM-01-9382
Electrochemical Reactions of Dihydroazaazulanones Possessing a Spirocyclic Moiety: Ring Cleavages of the Spiro-rings, Hydrogen Migrations and Formations of Azaazulanones

Katsuhiro Saito* and Ryosuke Ueno

*Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan

Abstract

Electrochemical oxidations of dihydroazaazulanones possessing a spirocyclic moiety afforded two types of dihydroazaazulanones and one type of azaazulanones. The reaction is considered to proceed via a ring cleavage of the spiro-three membered ring followed by a hydrogen migration.

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Communication | Regular issue | Vol 57, No. 2, 2002, pp. 223 - 228
Published online:
DOI: 10.3987/COM-01-9397
Nucleophilic Substitution Reaction of 5-t-Butyl-2-methoxy-3H-azepine with Alkoxides and Alkyllithium Reagents: A Formation of Bis(5-t-butyl-3H-azepin-2-yl)methane Having a Vinamidine Conjugation

Kyosuke Satake,* Yasuhiro Kubota, Hideki Okamoto, and Masaru Kimura

*Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

Reaction of 5-t-butyl-2-methoxy-3H-azepine (2) with nuclephiles (alkoxides or t-butyllithium) gave respective substitution product at 2-position of the ring. Unexpectedly, when methyllithium was used as a nucleophile, bis(5-t-butyl-3H-azepin-2-yl)methane (7), the structure of which found to be tautomeric vinamidine (7a,b), was formed. Tautomerization between 7 and 7a,b was characterized spectroscopically and theoretically based on the levels of B3LYP/6-31G(d).

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Communication | Regular issue | Vol 57, No. 2, 2002, pp. 229 - 234
Published online:
DOI: 10.3987/COM-01-9415
Stereoselective C-Allylation of 1-C-Alkyl-2,3,4,6-tetra-O-benzyl-D-glucopyranoses with Allyltrimethylsilane

Takashi Yamanoi* and Yoshiki Oda

*The Noguchi Institute, 1-8-1, Kaga, Itabashi-ku, Tokyo 173-0003, Japan

Abstract

The reaction of 1-C-alkyl-2,3,4,6-tetra-O-benzyl-D-glucopyanoses with allyltrimethylsilane in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate gave the corresponding C-allylated C-alkyl glucopyranosides in good yields. This C-allylation proceeded with high α-stereoselectivity.

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Communication | Regular issue | Vol 57, No. 2, 2002, pp. 235 - 240
Published online:
DOI: 10.3987/COM-01-9416
[2π+2σ] Type Cycloaddition Reactions of Iminotropone Derivatives with Naphtho[b]cyclopropene to Form Cyclic Amine Compounds

Katsuhiro Saito,* Katsuhiko Ono, Narie Ito, Naoe Tada, and Shinichi Ando

*Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan

Abstract

Reactions of iminotropone derivatives with naphtho[b]cyclopropene under the presence of a catalytic amount of AgBF4 afforded cyclic amine derivatives via [2π+ 2σ] type cycloaddition reactions. On the other hand, a reaction using a tropone hydrazone derivative without a catalysis formed a substituted hydrazone via a σ-bond rupture of the cyclopropene ring.

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Communication | Regular issue | Vol 57, No. 2, 2002, pp. 241 - 244
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DOI: 10.3987/COM-01-9420
Ruthenium-catalyzed Ring-opening Cross-Metathesis Reaction of 2-Azabicyclo[2.2.1]hept-5-en-3-one

Minoru Ishikura,* Makoto Saijo, and Ayako Hino

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

Abstract

An examination of the ring-opening cross-metathesis reaction of 2-azabicyclo[2.2.1]hept-5-en-3-one (ABH) (1a) with allyltrimethylsilane in the presence of Grubbs’ catalyst showed that a pair of regioisomeric products (2) (R=Boc) and (3) (R=Boc) could be isolated instead of the known regioselective formation of 2 (R=Boc).

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Paper | Regular issue | Vol 57, No. 2, 2002, pp. 245 - 257
Published online:
DOI: 10.3987/COM-01-9379
Reactions of 5,5-Dimethyl-4-methylene-1,3-dioxolan-2-one with Amines in the Presence of Palladium Catalyst

Min Shi,* Yu-Mei Shen, and Ya-Jun Chen

*State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, 354 Finglin Lu, Shanghai 200032, China

Abstract

In the reaction of 5,5-dimethyl-4-methylene-1,3-dioxolan-2-one with primary amines in the presence of Pd(0) catalyst, the 3-alkyl-4-hydroxy-4,5,5-trimethyloxazolidin-2-ones (1) are obtained as the major products, along with the formation of ring opened products at room temperature. On the other hand, 3-alkyl-5,5-dimethyl-4-methyloxazolidin-2-ones (2) are obtained as reaction products in high yields at high temperature. But in the absence of Pd(0) catalyst, the ring opened compounds alkylcarbamic acid 1,1-dimethyl-2-oxopropyl esters (3) are formed exclusively. In addition, in the reaction of 5,5-dimethyl-4-methylene-1,3-dioxolan-2-one with secondary amines, the ring opened compounds were obtained as the sole products. A plausible mechanism for the formation of 1 and 2 is proposed.

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Paper | Regular issue | Vol 57, No. 2, 2002, pp. 259 - 267
Published online:
DOI: 10.3987/COM-01-9388
A Concise Synthesis of the Natural Carbazole Mukonine

Alejandra Zempoalteca and Joaquín Tamariz*

*Departamento de Químíca Orgánica, Escuela Nacional de Ciencias Biológicas, I. P. N., Prol. Carpio y Plan de Ayala S/N,11340, Mexico, D.F.

Abstract

A short and total synthesis of the natural carbazole mukonine (1) is described, based on a regioselective Diels-Alder reaction of N-phenyl 4,5-dimethylidene-2-oxazolidinone (9) with methyl propiolate (10). Successive transformation of the cycloadduct in one step to the corresponding phenylarylamine (16), and palladium promoted cyclization of the latter provided carbazole (1).

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Paper | Regular issue | Vol 57, No. 2, 2002, pp. 269 - 292
Published online:
DOI: 10.3987/COM-01-9392
An Efficient Transformation of Substituted N-Acyl-α-dehydro(1-naphthyl)alanines into 1,2-Dihydrobenzo[f]quinolinone Derivatives via Photoinduced Intramolecular Electron Transfer

Toyohisa Motohashi, Kei Maekawa, Kanji Kubo, Tetsutaro Igarashi, and Tadamitsu Sakurai*

*Laboratory of Organic Chemistry, Faculty of Technology, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan

Abstract

The irradiation of substituted (Z)-N-acyl-α-dehydro(1-naphthyl)alanines (1) having the dialkylamino donor on the carboxamide side chain in methanol was found to give 1,2-dihydrobenzo[f]quinolinone derivatives (2) in good yields, which were formed via the electron-transfer reaction in the excited-state (E)-isomers, while intramolecular photocyclization reactions in the (Z)- and (E)-isomers afforded minor amounts of benzo[f]isoquinolines (3) and 1-azetines (4), respectively. The replacement of the N-acetyl group by the benzoyl (having stronger electron-withdrawing ability and larger steric bulkiness than the former) increased the selectivity for 2 and 4, and this increased selectivity was mainly reflected in a great lowering of that for 3.

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Paper | Regular issue | Vol 57, No. 2, 2002, pp. 293 - 305
Published online:
DOI: 10.3987/COM-01-9404
Stereoselective Synthesis of Substituted Tetrahydropyran Rings via 6-exo and 6-endo Selenoetherification

Carmela Aprile, Michelangelo Gruttadauria,* Paolo Lo Meo, Serena Riela, and Renato Noto

*Dipartimento di Chimica Organica “E. Paternò”, Università di Palermo, Viale delle Scienze-Parco d’Orleans II, 90128 Palermo, Italy

Abstract

Eight unsaturated alcohols were cyclized by selenoetherification in 6-exo or 6-endo manner to give substituted tetrahydropyran rings. Yields, regio- and stereoselectivities were discussed in terms of steric and electronic effects such as Se-O interaction. For the first time examples of the use of silica gel in selenoetherification and the effect of the X- counter ion of PhSe+ on the reaction course are discussed. These effects are related to the occurrence of Se-O interaction.

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Paper | Regular issue | Vol 57, No. 2, 2002, pp. 307 - 316
Published online:
DOI: 10.3987/COM-01-9407
Synthesis, 1H and 13C NMR Study of Pyrazoles Derived from Chiral Cyclohexanones (3-Methylcyclohexanone, Menthone, Pulegone, Dihydrocarvone and Carvone)

Robert Faure, Aline Frideling, Jean-Pierre Galy,* Ibon Alkorta, and José Elguero

*Laboratoire de Valoristation de la Chime Fine, Facluté des Sciences et Techniques de Saint Jérôme, Université d’Aix-Marseille III, Avenue Escardille Normandie Niemen (Case 552), 13397 Marseille Cedex 13, France

Abstract

The 1H and 13C chemical shifts of four tetrahydroindazoles (two of them existing as diastereomeric mixtures) and one aldazine were measured and assigned. These compounds were obtained from monoterpenic ketones (R)-(+)-3-methylcyclohexanone, (2S,5R)-(-)-menthone, (R)-(+)-pulegone, (5R)-(+)-dihydrocarvone, and (R)-(-)-carvone in a two-step procedure. The annular tautomerism in CDCl3 solution was calculated and compared with ab initio calculations (B3LYP/6-31G*).

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Note | Regular issue | Vol 57, No. 2, 2002, pp. 317 - 322
Published online:
DOI: 10.3987/COM-01-9377
A Preparative Route to Fused 4-Hydroxy-3-phenylindeno(benzothieno)pyridin-2-ones

Arielle Genevois-Borella, Marc Vuilhorgne, and Serge Mignani*

*Centre de Recherche de Vitry-Alfortville, Aventis Pharma S.A., 13, Quai Jules Guesde, BP 14, 94403, Vitry-sur-Seine Cedex, France

Abstract

Syntheses of fused 4-hydroxy-3-phenylindeno(benzothieno)-pyridin-2-one derivatives (1a,b) are described.

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Note | Regular issue | Vol 57, No. 2, 2002, pp. 323 - 326
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DOI: 10.3987/COM-01-9386
Preparation of a Useful Synthetic Precursor, 2-Substituted 4(3H)-Quinazolinone: Directed Lithiation and N3-Deprotection of 3-t-Butoxycarbonyl-4(3H)-quinazolinone

Osamu Sugimoto,* Yasuhiro Yamauchi, and Ken-ichi Tanji*

*Laboratory of Organic Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan

Abstract

Directed lithiation of 3-t-butoxycarbonyl-4(3H)-quinazolinone using LDA was accomplished to afford 2-substituted 3-t-butoxycarbonyl-4(3H)-quinazolinones. The t-butoxycarbonyl group of these products was easily deprotected to give key intermediates for the synthesis of quinazoline derivatives, 2-substituted 4(3H)-quinazolinones, in good yield.

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Note | Regular issue | Vol 57, No. 2, 2002, pp. 327 - 336
Published online:
DOI: 10.3987/COM-01-9391
Formal Total Synthesis of Macrosphelide (+)-A, Effect on Marcolactonization Depended upon the Lactone Formation Position

Hiroshi Nakamura, Machiko Ono, Miho Makino, and Hiroyuki Akita*

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

Abstract

Formal total synthesis of (+)-macrosphelide A (1) was achieved based on macrolactonization via path B from a seco-acid (3) and path C from a seco-acid (4). The yield of macrolactonization via paths B and C were 18 and 59%, respectively.

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Note | Regular issue | Vol 57, No. 2, 2002, pp. 337 - 340
Published online:
DOI: 10.3987/COM-01-9399
The Absolute Configuration of Leiocarpin B

Qing Mu, Weidong Tang, Chaoming Li, Yongping Xu, Handong Sun, Liguang Lou, Xiaojiang Hao,* Bin Xu, and Chang Qi Hu

*Laboratory of Phytochemistry, Kunming Institute of Botany, The Chinese Academy of Sciences, Kunming, Yunnan 650204, China

Abstract

Leiocarpin B, a natural compound isolated from the plant, Goniothalamus leiocarpus, is a styryllactone showing anticancer activity in vitro test. Its chemical structure and relative configuration were determined by means of spectral methods and X-Ray crystallographic analysis. In the present investigation, its absolute configuration was determined using the Mosher’s method and its anticancer activities were tested in vivo.

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Note | Regular issue | Vol 57, No. 2, 2002, pp. 341 - 351
Published online:
DOI: 10.3987/COM-01-9402
Synthesis and Cytotoxic Activity of Isoacronycine and Its Derivatives

Prokopios Magiatis, Sofia Mitaku,* Alain Pierré, and Ghanem Atassi

*Laboratory of Pharmacognosy, School of Pharmacy, University of Athens, Panepistimiopolis-Zografou, Athens GR-15771, Greece

Abstract

Condensation of N-methyl-1,3-dihydroxyacridone with 3-methyl-2-butenal led selectively to norisoacronycine, which upon methylation gave isoacronycine. Functionalization of the 1,2 double bond of isoacronycine led to derivatives with reduced cytotoxicity compared with the corresponding ones deriving from acronycine. Two very interesting exceptions were 1-hydroxy-1,2-dihydroisoacronycine (14) and its acetate (16), which showed strong induction of apoptosis.

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Note | Regular issue | Vol 57, No. 2, 2002, pp. 353 - 356
Published online:
DOI: 10.3987/COM-01-9410
The Crystal and Molecular Structure of 2,3,5,6-Tetraphenyl-1,4-dithiin

Ian W. Jones and Patrick E. Hoggard*

*Department of Chemistry, Santa Clara University, 500 El Camino Real, Santa Clara, California 95053-270, U.S.A.

Abstract

The phenyl rings in 2,3,5,6-tetraphenyl-1,4-dithiin have neither of the two most obvious configurations: all perpendicular to the dithiin ring (paddlewheel), or parallel to the dithiin double bonds (butterfly). Instead, there are two phenyls in each orientation.

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Note | Regular issue | Vol 57, No. 2, 2002, pp. 357 - 360
Published online:
DOI: 10.3987/COM-01-9413
A Synthesis of Orixiarine

Raju Nandha Kumar, Senniappan Thamarai Selvi, Thangaraj Suresh, and Palathurai Subramaniam Mohan*

*Department of Chemistry, Bharathiar University, Coimbatore - 641 046, Tamil Nadu, India

Abstract

A synthesis of the quinoline alkaloid, orixiarine was achieved starting from N-methylaniline and isopropyl methyl ketone.

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Review | Regular issue | Vol 57, No. 2, 2002, pp. 361 - 404
Published online:
DOI: 10.3987/REV-01-545
Recent Advances in the Synthesis and Transformations of Heterocycles Mediated by Fluoride Ion Activated Organosilicon Compounds

Edgars Abele and Edmunds Lukevics*

*Latvian Institute of Organic Synthesis, 21 Aizkraukles Street, Riga, LV-1006, Latvia

Abstract

Modern methodologies of preparation and transformation of three-, four-, five- and six-membered heterocycles and their functional groups using silanes in the presence of fluoride ion have been reviewed. Syntheses of large sized heterocyclic compounds are also included.

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18 data found. 1 - 18 listed