Special Issue

Masatomo Hamana's Special Issues, Vol. 33, No. 2, 1992

53 data found. 31 - 53 listedFirst Previous
Paper | Special issue | Vol 33, No. 2, 1992, pp. 701 - 712
Published online:
DOI: 10.3987/COM-91-S72
Synthesis of (±)-Prosurugatoxin and Ring Transformation of Prosurugatoxin into Surugatoxin

Shoji Inoue,* Kunisuke Okada, Hideo Tanino, and Hisae Kakoi

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

Abstract

Synthetic identification of prosurugatoxin and a possible mechanism for the ring transformation of prosurugatoxin into surugatoxin are presented.

PDF (246KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 713 - 742
Published online:
DOI: 10.3987/COM-91-S80
An Enantiocontrolled Route to Protomycinolide IV and Its Presumed Biogenetic Precursors Using (S)-O-Benzylglycidol

Seiichi Takano,* Yoshinori Sekiguchi, Youicho Shimazaki, and Kunio Ogasawara

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

Starting with (S)-O-benzylglycidol (9) as only chiral building block, a formal synthesis of protomycinolide IV (1) and the first syntheses of its presumed biogenetic precursors methyl epimycinonate I (2), methyl mycinonate I (3), methyl mycinonate II (4), and decarboxymycinonic acid III (5), have been achieved via the eight-carbon unit (8) as a common intermediate.

PDF (791KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 743 - 755
Published online:
DOI: 10.3987/COM-91-S79
An Enantiocontrolled Route to the C11-17 Segment of Mycinamicins III and IV

Seiichi Takano,* Yoshinori Sekiguchi, and Kunio Ogasawara

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

An enantiocontrolled route to the common C11-17 segment (2) of mycinamicins III (1a) and IV (1b) has been developed starting from the chiral α-hydroxyacetylene (6) obtained from (E)-4-benzyloxybut-2-en-l-o1 (3).

PDF (338KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 757 - 762
Published online:
DOI: 10.3987/COM-91-S81
Synthesis of 2-Methylthio-3H-indol-3-one 3-Oximes from 1-(-N-Arylamino)-1-methylthio-2-nitroethenes

Timothy Kearney, John A. Joule,* and Arther Jackson

*Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, U.K.

Abstract

I-(N-Arylamino)-1-methylthio-2-nitroethenes, prepared by reaction of the arylamine with 1,1-bis(methylthio)-2-nitroethene, are converted into 2-methylthio-3H-indol-3-one 3-oximes by treatment with triflic acid at room temperature.

PDF (173KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 763 - 774
Published online:
DOI: 10.3987/COM-91-S82
Condensation of 5-Aminoisothiazoles with N-Methylimodoyl Chloride. Ring-Transformation with Participation of 10-S-3 Type Sulfurne

Katsuo Ohkata, Yuko Watanabe, Yoshihiko Ohyama, and Kin-ya Akiba*

*Department of Chemistry, Faculty of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8526, Japan

Abstract

In the presence of 1,4-diazabicyclo[2.2.2]octane, 5-amino-3-methylisothiazole (4a) in acetonitrile condensed with N -methyl-p-chlorobenzimidoyl chloride (5a) to afford two kinds of compounds along with several minor products. One of the two was 1 : 1 condensed product (6a) and the other was 2 : 1 condensed product (7a). The latter compound was obtained in higher yield when an excess 4a was treated with 5a. On the other hand, in the absence of the additional base, 2 : 3 condensed compound (8a) was isolated as a major product besides 6a and 7a. 8a was obtained by treatment of 7a with 2 equiv. of imidoyl chloride in 21% yield. Reaction of 5-amino-3-phenylisothiazole (4b) with imidoyl chloride (5a,b) furnished the analogous products. On the other hand, condensation of 5-amino-3-phenylisoxazole (4c) with 5a furnished the oxygen analogue (6d) corresponding to 6b as a sole isolated product. The formation of 7 is explained by ring-transformation from isothiazole into thiadiazole via hypervalent 10-S-3 type sulfurane (B).

PDF (219KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 775 - 790
Published online:
DOI: 10.3987/COM-91-S83
Facile and General Synthesis of 8-Substituted 2-Methylthiopurin-6-ones

Tomohisa Nagamatsu, Hiroo Yamasaki, and Fumio Yoneda*

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

Abstract

A variety of 3-methyl-6-oxo-2-thioxo-1,2,3,6-tetrahydropurine (3a) and its 8-substituted derivatives (3b-o) were synthesized by oxidative cyclization of the reaction product of 5,6-diamino-1-methyl-2-thiouracil (1) with an appropriate aldehyde or 6-amino-5-benzylideneamino-1-methyl-2-thiouracils (2d-o) in the presence of diethyl azodicarboxylate (DEAD). In addition, the oxidative cyclization of 4-amino-5-benzylideneamino-3-methyl-2-methylthiopyrimidin-6(3H)-ones (5d-o) in the presence of DEAD gave the corresponding 8-aryl-3-methyl-2-methylthio-6-oxo-3,6-dihydropurines (4d-o), which were identical with the compounds prepared by methylation of 3d-o , respectively. 2-Methylthio-6-oxo-1,6-dihydropurine (8a) and its 8-alkyl and 8-aryl derivatives (8b-h) were synthesized from 4,5-diamino-2-methylthiopyrimidin-6(1H)-one (6) or 4-amino-5-benzylideneamino-2-methylthiopyrimidin-6(1H)-ones (7d-h) in a similar manner as above.

PDF (350KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 791 - 800
Published online:
DOI: 10.3987/COM-91-S84
Nucleophilic Substitution Reaction of 4-Bromo-benzo[1,2-c;3,4-c']bis[1,2,5]thiadiazole and Reduction of Hydroxy and MEethoxy Derivative to the Corresponding 1,2,3,4-Benzenetetraaamine

Shuntaro Mataka,* Youji Ikezaki, Kazufumi Takahashi, Akiyoshi Tori-i, and Masashi Tashiro

*Instituete of Advanced Material Study, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan

Abstract

Bromobenzo[1,2-c;3,4-c’]bis[1,2,5]thiadiazole (2a) reacted with a series of nucleophiles to give alkoxy-, propylthio-, and amino-substituted derivatives (3,8 and 9 ). Reaction of 2a with allyl alcohol at room temperature gave allyl ether (3e) which, on being heated, rearranged to 4-allyl-5-hydroxy derivative (4). Treatment of methoxy and ethoxy derivatives (3a and 3b) with hydrobromic acid gave hydroxy compound (5). Reduction of 3a and 5 gave the corresponding 1,2,3,4-benzenetetraamine (10 ·3HCl ) and (11 ·2HCl), respectively. Reduction of piperidino derivative (9b) gave a mixture of hydrochlorides of 1,2,3,4-benzenetetraamine (1a),11, and 5-piperidino-1,2,3,4-benzenetetraamine (12).

PDF (268KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 801 - 811
Published online:
DOI: 10.3987/COM-91-S86
A New Evidence for the Presence of a Spiroindolenium Species in the Pictet-Spengler Reaction

Tomohiko Kawate, Masako Nakagawa,* Koreharu Ogata, and Tohru Hino*

*Faculty of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

The Pictet-Spengler reaction of the imine (9) with chloro (-)-diisopinocamphenylborane yielded optically active spiroindolines (14) and (15), providing a new evidence for the presence of a spiroindolenium intermediate.

PDF (270KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 813 - 818
Published online:
DOI: 10.3987/COM-91-S87
Synthesis and Reaction of Tributylstannylpyrazoles

Takao Sakamoto, Futoshi Shiga, Daishi Uchiyama, Yoshinori Kondo, and Hiroshi Yamanaka*

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

1,3-Dipolar cycloaddition reaction of diazomethane and ethyl diazoacetate with tributylstannylacetylenes occurred regioselectively to afford the corresponding 3(5)-tributylstannylpyrazoles. The cycloadtitiin reaction of 3-phenylsydnone with the stannylacetylenes proceeded also regioselectively, and 3-tributylstannyl-1-phenylpyrazoles were isolated. 4-Tributylstannyl- and 5-tributylstannyl-1-phenylpyrazole were prepared by the stannylatiin of 4-lithio- and 5-lithio-1-phenylpyrazoles with tributylstannyl chloride. lodination, benzoylation, and phenylation of the stannylpyrazoles were examined.

PDF (158KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 819 - 830
Published online:
DOI: 10.3987/COM-91-S88
New C-N-C Bond Formation Reaction Using Nitrogenation-Transmetallation Process. Novel Ring Construction of Indole and Quinoline Derivatives

Miwako Mori,* Yasuhiro Uozumi, and Masakatsu Shibasaki

*Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan

Abstract

Ketones and aryl or vinyl halides couple to give divinyl- or arylvinylamines in the presence of the titanium-isocyanate complex [3THF·Mg2Cl2O·TiNCO] (1) and a palladium catalyst, via transmetallation of the titano imine complex (3) with aryl- or vinylpalladium bromide.

PDF (251KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 831 - 841
Published online:
DOI: 10.3987/COM-91-S89
An Efficient Synthesis of Optically Active 4-Benzyloxy-3-hydoroxy-1-butyne and Its Cross-Coupling Reaction

Seiichi Takano,* Masashi Akiyama, Takumichi Sugihara, and Kunio Ogasawara

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

An efficient procedure for the synthesis of optically active 4-benzyloxy-3-hydroxy-1-butyne (12: R=H) has been established starting with optically active tartrate ester. Cross-coupling reaction of the resulted acetylene (12: R=H) with some aromatic halides (13a~h) and transformation of the arylacetylenes (14a~h), thus obtained, into the allylic amine derivatives (17a~h) have also been examined via the allylic alcohol intermediates (15a~h) by sequential stereoselective reduction and [3,3] sigmatropic rearrangement.

PDF (258KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 843 - 849
Published online:
DOI: 10.3987/COM-91-S91
4-Ethoxymethylene-2-phenyl-5(4H)-oxazolene as a Synthon for the synthesis of Some 2H-Pyran-2-ones

Vladimir Kepe, Marijan Kocevar,* Andrej Petric, Slovenko Polanc, and Bojan Vercek

*Department of Chemistry and Chemical Technology, University of Ljubljana, Murnikova 6-P.O.B.537 61000 Ljubljana, Slovenia

Abstract

Treatment of 4-ethoxymethylene-2-phenyl-5(4H)-oxazolone with activated methylene compounds under acidic or basic conditions leads to 2H-pyran-2-ones and fused pyran-2-ones . On the other hand, methyl(3-benzoylamino-5-methoxycarbonyl-2-oxo-2H-pyran-6-yl)acetate (4) has also been prepared by a one-pot synthesis from dimethyl 1,3-acetonedicarboxylate, diethoxymethyl acetate, hippuric acid and acetic anhydride .

PDF (117KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 851 - 858
Published online:
DOI: 10.3987/COM-91-S92
Novel One Step Transformation of Carbomates into Amides

Masataka Ihara, Akihito Hirabayashi, Nobuaki Tanigichim and Keiichiro Fukumoto*

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

A novel method for the one step conversion of carbamates into amides was developed by the action of acyl chlorides and sodium iodide.

PDF (157KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 859 - 891
Published online:
DOI: 10.3987/COM-91-S96
Δ3-Thiazolines, Δ4-Thiazolines and Thiazoles from Penem Antibiotics

Giuseppina Visentin, Ettore Perrone,* Daniela Borghi, Vincenzo Rizzo, Marco Alpegiani, Angelo Bedeschi, Riccardo Corigli, Giovanni Rivola, and Giovanni Franceschi

*Farmitalia Carlo Erba R&D, Via dei Gracchi 35, 20146 Milano, Italy

Abstract

Upon cleavage of the β-lactam ring, penems are converted to unstable Δ4-thiazolines, which epimerize at the ex-C-5 position, lose a nucleofugal group at C-2’ (if originally present), tautomerize to Δ3-thiazolines, or suffer hydrolytic decomposition. Other chemical events, observed on some substrates under determinate conditions, include protomeric and oxidative aromatization to thiazoles (followed by side-chain reactions, such as epimerization at C-6 , decarboxylation, dehydration, retro-aldol condensation), and conjugate addition of external and internal thiols. Mention is made of the chemical, biochemical and pharmacological significance of these findings .

PDF (886KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 893 - 903
Published online:
DOI: 10.3987/COM-91-S97
Synthesis of 1,2,4-Triazines; XIII. Regioselective Synthesis of Trialkyl-1,2,4-triazines

Tadashi Ohsumi and Hans Neunhoeffer*

*Institüt fur Organische Chemie, Technische Hochschule Darmstadt, Petersenstrasse. 22 64287 Darmstadt, Germany

Abstract

Trialkyl-1,2,4-triazines (3) were prepared by heating α-oxoacylhydrazones (4) or N,N-dimethylaminomethylene hydrazones (19) with ammonium acetate at 100°C . The solvent plays an important role in the regioselectivity of these reactions.

PDF (244KB)
Paper | Special issue | Vol 33, No. 2, 1992, pp. 905 - 929
Published online:
DOI: 10.3987/COM-91-S100
Ptrimides, XXXII: Synthesis and Properties of Pyrido[2,3-d]pyrimidine-2,4-diones (5-Deazalumazines)

Mathias Pfleiderer and Wolfgang Pfleiderer*

*Fakultät für Chemie, Universität Konstanz, Posttach 5560, D-7750 Konstantz, Germany

Abstract

Pyrido[2,3-d]pyrimidine-2,4-dione - (8) and its N -methyl derivatives (9 -11) as well as the corresponding 6-nitro analogues (12-15) have been synthesized by condensation reactions from 6-aminouracils (4 -7) . Reduction of compounds (4-7) led to the 6-aminopyrido[2,3-d ]pyrimidine -2,4-diones (18-21) . Diazotization of the amino group afforded two crystalline diazonium salts (26,27), the Sandmeyer reaction gave 6-halo compounds (28-31) and coupling reactions with secondary amines led to a series of 6-triazenopyrido[2,3-d] pyrimidine-2,4-diones (32-39). Treatment of the 6-nitropyrido[2,3-d ]pyrimidine-2,4-diones (12-14) with sodium borohydride result ed in a reduction of the pyrido moiety to form the 5,6,7,8-tetrahydro derivatives (40-42) .

PDF (492KB)
Review | Special issue | Vol 33, No. 2, 1992, pp. 931 - 972
Published online:
DOI: 10.3987/REV-91-SR1
Recent Advances in the Chemistry of as-Triazinuum Salts

Oleg Chupakhin,* Sergei Alexeev, Boris Rudakov, and Valery Charushin

*Urals Polythcnical Institute, Sverdlovsk, 620002, Russia

Abstract

Recent studies on protonation and alkylation of as-triazines and the synthesis of N-alkyl-as -triazinium salts are summarized. The reactions of as -triazinium cations and the features of their chemical behaviours in comparison with those of neutral species are discussed.

PDF (725KB)
Review | Special issue | Vol 33, No. 2, 1992, pp. 973 - 1010
Published online:
DOI: 10.3987/REV-91-SR2
Haloalkyl Isothiocynates, Useful and Versatile Reagents in Heterocyclic Chemistry

Martín Avalos, Reyes Babiano, Pedro Cintas, José Luis Jiménez, and Juan Carlos Palacios*

*Departamento de Química Orgánica, Universidad de Extremadura, Avenida de Elvas s/n, 06071-Badajoz, Spain

Abstract

This review deals with the preparations and reactions of haloalkyl isothiocyanates, which constitute useful and versatile tools in the synthesis of heterocycles.

PDF (820KB)
Review | Special issue | Vol 33, No. 2, 1992, pp. 1011 - 1049
Published online:
DOI: 10.3987/REV-91-SR3
Heterocyclic N-Oxides and N-Imides

Alan R. Katritzky* and Jamshed N. Lam

*Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, FL 32611-7200, U.S.A.

Abstract

Heterocyclic N -oxides and N -imides show a variety of fascinating reactions. This review exemplifies their preparation, discusses their structures, and considers some of their reactions.

PDF (587KB)
Review | Special issue | Vol 33, No. 2, 1992, pp. 1051 - 1078
Published online:
DOI: 10.3987/REV-91-SR5
Synthesis of β-Oxygenatd γ-amino Acids and γ-Oxygenated γ-Amino Acids from α-Amino Acids

Tsutomu Yokomatsu, Yoko Yuasa, and Shiroshi Shibuya*

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

Abstract

A diastereoselective synthesis of 2-amino alcohols toward a synthesis of β-oxygenated γ-amino acids, γ-oxygenated δ-amino acids, and related compounds was summarized.

PDF (603KB)
Review | Special issue | Vol 33, No. 2, 1992, pp. 1079 - 1100
Published online:
DOI: 10.3987/REV-91-SR8
Synthesis of Oxygen-containing Heterocycles Using Palladium(II) Catalysts

Takahiro Hosokawa and Shun-ichi Murahashi*

*Department of Chemistry, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan

Abstract

Alkenes, dienes, and alkynes bearing hydroxy groups, when treated with palladium(II) catalysts, afford a variety of oxygen-containing heterocycles via cyclizations involving intramolecular oxypalladation as a key step. Trapping the oxypalladation intermediates with CO also creates useful entries to xygen-containing heterocycles. Synthetic aspects of these cyclizations as well as the catalyses of palladium(II) are surveyed in this article.

PDF (395KB)
Review | Special issue | Vol 33, No. 2, 1992, pp. 1101 - 1128
Published online:
DOI: 10.3987/REV-91-SR9
Some Stereochemical Aspects of Bisquinolizidine Alkaloids Sparteine Type

Wladyslaw Boczon*

*Department of Stereochemistry, Facluty of Chemistry, Adam Mickiewicz University, ul. Grunwaldzka 6, 60-780 Poznán, Poland

Abstract

This review presents some considerations on the influence of inter- and extramolecular factors of bisquinolizidine alkaloids on their stereochemistry, chemical and physicochemical properties / also: proton-acceptor / and configurational-conformational equilibria.

PDF (648KB)
Review | Special issue | Vol 33, No. 2, 1992, pp. 1129 - 1153
Published online:
DOI: 10.3987/REV-91-SR10
A General Descriotin of the Reactivity of Heteroaromatic Compounds Based on the Donor-Acceptor Concept

Mikael Begtrup*

*Department of Organic Chemistry, Royal School of Pharmacy, Universitetsparken 2, DK-2100 Copenhagen, Denmark

Abstract

The reactivity of heteroaromatic ring- and exocyclic α-positions in ionic processes has been described in terms of 5 acceptor and 4 donor types, each in 5 levels of potency. The system is useful for prediction of reactivity and regioselectivity.

PDF (425KB)
53 data found. 31 - 53 listedFirst Previous