Special Issue

Yuichi Kanaoka's Special Issues, Vol. 59, No. 1, 2003

48 data found. 31 - 48 listedFirst Previous
Paper | Special issue | Vol 59, No. 1, 2003, pp. 237 - 243
Published online:
DOI: 10.3987/COM-02-S27
A Facile Synthesis of Benzofuran Derivatives: A Useful Synthon for Preparation of Trypsin Inhibitor

Haruo Sekizaki, Kunihiko Itoh, Eiko Toyota, and Kazutaka Tanizawa*

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

Abstract

Mono-substituted 2-methylbenzo[b]furans were prepared by Claisen rearrangement of corresponding allyl phenyl ethers and subsequent bis(benzonitrile)palladium(II) chloride-mediated cyclization of o-allylphenols.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 245 - 255
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DOI: 10.3987/COM-02-S28
Synthesis of Protected (2S,6S,8S)-Indolizin-9-one Amino Acid

Masaki Shimizu, Hideo Nemoto, Hiroko Kakuda, and Hiroki Takahata*

*Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan

Abstract

First synthesis of (2S,6S,8S)-indolizidin-9-one amino acid starting from 1,6-heptadiene has been described.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 257 - 264
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DOI: 10.3987/COM-02-S29
Synthesis of Quinolinealkyl-Phosphine Oxides and - Phosphonates from N-Arylimines Derived from Phosphine Oxides and Phosphonates

Francisco Palacios,* Javier Vicario, and Domitila Aparicio

*Departamento de Química Orgánica, Facultad de Farmacia, Universidad del País Vasco, Apartado 450, 01080 Vitoria-Gasteiz, Spain

Abstract

Quinolinealkylphosphine oxides are obtained by thermal treatment of N-arylimines derived from phosphine oxides with N,N-dimethylformamide diethyl acetal (DMF-DEA). In a similar manner, quinolinealkylphosphonates are obtained by reaction of DMF-DEA with N-arylimines derived from phosphonates or from their precursors, arylamines and carbonyl derivatives.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 265 - 274
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DOI: 10.3987/COM-02-S30
Photochemistry of 2,3-, 4,5,- and 2,7-Azepinobenzodioxins: Photochemical Rearrangement of 2,7-Azepinobenzodioxin to 2,3- and 4,5-Azepinobenzodioxins, and Formation of 2,3-Dihydrodibenzodioxin from 2,3- and 4,5-Azepinobenzodioxins

Katsuhiro Saito,* Katsuhiko Ono, Yoshitaka Emoto, and Kentaro Miyanaga

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

Abstract

Photoirradiation of a 2,7-azepinobenzodioxin with a low pressure mercury lamp afforded 2,3- and 4,5-azepinobenzodioxins, a 2,3-dihydrodibenzodioxin, and an azepine derivative. The analogous irradiation of a 2,3-azepinobenzodioxin gave a 2,3-dihydrodibenzodioxin. On the other hand, a 4,5-azepinobenzodioxin formed a dihydropyrrole derivative accompanied by a 2,3-dihydrodibenzodioxin. The effects of solvents and sensitizers were investigated.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 275 - 281
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DOI: 10.3987/COM-02-S31
Oxidation Products of Strictosamide by Iodosobenzene Diacetate

Hideyuki Shigemori, Toshinori Kagata, and Jun’ichi Kobayashi*

*Graduate School of Pharmaceutical Science, Hokkaido University, Sapporo 060-0812, Hokkaido

Abstract

Oxidation of strictosamide(1), a representative monoterpene indole alkaloid, by iodosobenzene diacetate (IBD) gave compounds (2 - 6), among them the structure of 3 corresponded to an oxindole derived through oxidative cleavage between C-2 and C-3 of 1. A plausible mechanism of formation of 2 - 6 from strictosamide (1) by IBD oxidation is proposed.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 283 - 291
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DOI: 10.3987/COM-02-S33
The Aerial Oxidation of a Cobalt(II)-2-Aminomethylpyridine Complex: An Improved Method for Synthesis of 2,3,5,6-(Tetrapyridin-2-yl)Pyrazine

Kuniyoshi Ogura, Yoshihisa Kurasawa, Yoshimi Yamaguchi, and Yoshihisa Okamoto*

*Center for Natural Sciences, Kitasato University, 1-15-1, Kitasato, Sagamihara, Kanagawa 228-8555, Japan

Abstract

An excellent tridentate chelate compound for iron(II) ion, 2,3,5,6-(tetrapyridin-2-yl)pyrazine (2), was directly synthesized by aerial oxidation of a cobalt(II)-2-aminomethylpyridine complex. Oxidation pathways are also proposed.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 293 - 301
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DOI: 10.3987/COM-02-S35
Concise Synthesis of Fagaridine and Decarine, Phenolic Benzo[c]phenanthridine Alkaloids, Using the Palladium-assisted Biaryl Coupling Reaction

Takashi Harayama,* Tomonori Sato, Yuichiro Nakano, Hitoshi Abe, and Yasuo Takeuchi

*Faculty of Pharmaceutical Science, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

Total synthesis of fagaridine (5) and decarine (6), phenolic benzo[c]phenanthridine alkaloids, was accomplished via the aryl-aryl coupling reaction of bromo amides protected by an isopropyl group with palladium, followed by reduction with LiAlH4 and treatment with conc. HCl

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 303 - 316
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DOI: 10.3987/COM-02-S37
Intramolecular Photoreaction of Thiobarbiturates with an Alkenyl or a Benzyl Group in Their N-Alkyl Side Chain. Regioselective Synthesis of Ring-fused Pyrimidine Derivatives through Photocyclization of Mono- and Di- Thiobarbiturates

Haruko Takechi,* Hajime Takahashi, Reijiro Mahara, and Minoru Machida

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

Abstract

Upon irradiation, thiobarbiturates with an alkenyl (4,5) or a benzyl (14,15,21) group in their N-alkyl side chain give bi- and tri-cyclic fused pyrimidine derivatives through regioselective [2+2] photocycloaddition or Norrish type II reaction, respectively.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 317 - 322
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DOI: 10.3987/COM-02-S39
Synthesis of 2-Dimethylaminobenzazoles via a Guanidine Intermediate: Reaction of 2-Substituted Aniline Derivatives with 2-Chloro-1,1,3,3-Tetramethylformamidinium Chloride

Kosei Ohno,* Wakako Ishida (nee Kusakari), Kazuyuki Kamata, Kazuaki Oda, and Minoru Machida

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

Abstract

Reactions of 2-aminophenols, 2-aminothiophenol and o-phenylenediamines with 2-chloro-1,1,3,3-tetramethylformamidinium chloride proceeded easily via cyclization of guanidine intermediates to give the corresponding benzazoles having a dimethylamino group at 2-position.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 323 - 332
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DOI: 10.3987/COM-02-S43
Chiral Functionalization of 2(3H)-Thiazolone. New Route to Chiral Synthons for 2-Amino Thiols

Hirokazu Isozumi, Shigeki Hoshimoto, Hirofumi Matsunaga, and Takehisa Kunieda*

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

Abstract

Treatment of 3-[2(R)-methoxyethoxy- or 3-[2(R)-methoxyethoxyethoxy-7,7-dimethylbicyclo[2.2.1]heptane-1(S)-carbonyl]-2-thiazolones with Br2 / MeC(OMe)3 and C6H5SeCl / MeOH resulted in the diastereoselective formation of 4(S)-methoxy-5(S)-bromo- and 4(R)-methoxy-5(R)-phenylseleno-2-thiazolidinones, respectively, with high to excellent π-facial selectivity, but with opposite diastereofacial selection. The adducts thus obtained are potentially useful as chiral synthons for 2-amino thiols.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 333 - 345
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DOI: 10.3987/COM-02-S44
Preparation of Furans by Palladium-catalyzed Reaction of Acylchromates and Propargylic Tosylates

Masaki Nakamura, Motoki Yamane, Hidehiro Sakurai, and Koichi Narasaka*

*Department of Chemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

Abstract

Substituted furans are prepared by the palladium-catalyzed reaction of propargylic tosylates with acylchromates. The reaction is initiated by the oxidative additiion of propagylic tosylates to palladium(0) complexes to give 1,2-propadienylpalladium(II) complexes, which in turn react with acylchromates to form 1,2-propadienyl ketones. Then 1,2-propadienyl ketones are transformed to furans by the action of in situ generated Cr(CO)5.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 347 - 358
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DOI: 10.3987/COM-02-S46
Stereoselective Synthesis of Fully Substituted δ-Lactone; The C1-C8 Fragment of Discodermolide

Takayuki Yakura, Tomoko Kitano, Masazumi Ikeda, and Jun’ichi Uenishi*

*Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan

Abstract

Baeyer-Villiger reaction of (2R,3S,4R)-4-tert-butyldimethyl-silyloxy-2-tert-butyldimethylsilyloxymethyl-3-methylcyclopentanone (5) gave (4R,5S,6R)-4-tert-butyldimethylsilyloxy-6-tert-butyldimethylsilyloxymethyl-5-methyltetrahydropyran-2-one (3) in 96% yield, which was transformed into the C1-C8 fragment (2) of discodermolide via (3R,4S,5S,6S)-6-allyl-4-tert-butyl-dimethylsilyloxy-3,5-dimethyltetrahydropyran-2-one (4).

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 359 - 368
Published online:
DOI: 10.3987/COM-02-S48
Reactions of Methyl 3-Bromoacetylazulene-1-carboxylate with 2-Aminopyridines and Related Compounds. Synthesis of Azulenes Bearing Imidazole-fused Nitrogen-Heterocycles

Yumiko Miyashita, Shigeru Kikuchi, and Kimiaki Imafuku*

*Department of Chemistry, Faculty of Science, Kumamoto University, Kurokami 2-39-1, Kumamoto 860-8555, Japan

Abstract

Methyl 3-bromoacetylazulene-1-carboxylate (1) reacted with 2-aminopyridines (2a-f) to give methyl 3-(imidazo[1,2-a]pyrid-2-yl)azulene-1-carboxylates (3a-f). Similarly, the reactions with 2-aminopyrimidines (5a-c) and 2-amiono-1,2,4-triazines (8a,b) gave the corresponding imidazo[1,2-a]pyrimidine- (6a-c) and imidazo[1,2-b][1,2,4]triazine-substitutrd azulenes (9a,b), respectively. Additionally, the substitution products (4e,f and 7c) were isolated.

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Paper | Special issue | Vol 59, No. 1, 2003, pp. 369 - 385
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DOI: 10.3987/COM-02-S49
Catalytic Enantioselective Synthesis of (20S)-Comptothecin Intermediates Using Cyanosilylation of Ketones Promoted by D-Glucose-derived Lanthanide Catalyst

Kanzo Yabu, Shuji Masumoto, Motomu Kanai, Wu Du, Dennis P. Curran, and Masakatsu Shibasaki*

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

Abstract

An efficient catalytic enantioselective synthetic route was developed for Curran’s versatile camptothecin intermediate (5). The key step is the catalytic enantioselective cyanosilylation of ketone (7) using a chiral samarium (Sm) complex. The target ketone cyanohydrin (6) was obtained with 90% ee using 2 mol % of the catalyst. A gadolinium (Gd) complex derived from the same chiral ligand could also be used as an enantioselective catalyst to synthesize Corey’s intermediate (11).

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Note | Special issue | Vol 59, No. 1, 2003, pp. 387 - 393
Published online:
DOI: 10.3987/COM-01-S1
Monoepoxidation of Humulene 2,3-Epoxide to Humulene 2,3;6,7-Diepoxides. Observation of the Rotation of the Double Bond Plane by 1H NMR Spectral Analysis and Conformation

Kiyoharu Hayano* and Katsura Mochizuki

*Chemistry Laboratory, Hokkaido College of Education, Ainosato, Sapporo, Hokkaido 002-8502, Japan

Abstract

The reaction of (6E,9E)-humulene 2,3-epoxide (7) with m-CPBA produced two known humulene 2,3;6,7-diepoxides (8 and 9), and careful analysis of the 1H NMR of 7 at various temperatures suggested an equilibrium of four possible conformations, CT, CC, TC and TT, over 0°C together with free rotation of the 9,10-double bond plane in 8 at 85°C.

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Note | Special issue | Vol 59, No. 1, 2003, pp. 395 - 398
Published online:
DOI: 10.3987/COM-02-S16
Effective Synthesis of a Carbon-linked Diazirinyl Fatty Acid Derivative via Reduction of the Carbonyl Group to Methylene with Triethylsilane and Trifluoroacetic Acid

Makoto Hashimoto,* Yasumaru Hatanaka, and Kensuke Nabeta

*Department of Bioresource Science, Obihiro Univ.of Agriculture and Veterinary Med., Inada-cho, Obihiro, Hokkaido 080-8555, Japan

Abstract

Friedel-Crafts acylation of the aryldiazirine with ω-ester-α-acyl halide and successive reduction of the carbonyl group to methylene with triethylsilane and trifluoroacetic acid gave diazirinylated fatty acids.

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Review | Special issue | Vol 59, No. 1, 2003, pp. 399 - 427
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DOI: 10.3987/REV-02-SR1
Photochemistry of Nitrogen-containing Thiocarbonyl Compounds

Masami Sakamoto* and Takehiko Nishio

*Department of Materials Technology, Faculty of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

Photochemical reactions of nitrogen-containing thiocarbonyl compounds, such as thioamides and thioimides, are reviewed. The thiocarbonyl compounds exhibit high photochemical reactivity for [2+2] photocycloaddtion with alkenes leading to thietanes; this is often followed by ring opening-reaction or rearrangement. Photochemical hydrogen abstraction of thioimides gives lactams and cyclic amines. Some thioamides show activity for cyclization via electron transfer, α-cleavage reaction, desulfurization and other miscellaneous reactions. The photochemical reaction of thioamides and thioimides provides not only a new photochemical aspect in the area of organic photochemistry but also a useful synthesis of nitrogen-containing heterocycles.

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Review | Special issue | Vol 59, No. 1, 2003, pp. 429 - 440
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DOI: 10.3987/REV-02-SR3
A General Route to Bridged Azabicyclic Compounds Using Radical Translocation/Cyclization Reactions

Tatsunori Sato and Masazumi Ikeda*

*Kyoto Pharmaceutical University, Misasagi-Shichonocho, Yamashina, Kyorto 607-8414, Japan

Abstract

This review summarizes a general route to bridged azabicyclic compounds using tributyltin hydride-mediated radical translocation/cyclization reactions.

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48 data found. 31 - 48 listedFirst Previous