Special Issue

Teruaki Mukaiyama's Special Issues, Vol. 52, No. 3, 2000

45 data found. 1 - 30 listed Next Last
Communication | Special issue | Vol 52, No. 3, 2000, pp. 1001 - 1004
Published online:
DOI: 10.3987/COM-99-S95
Stereoselective Synthesis of Optically Active β-Lactams by the Reaction of Chiral Imines Derived from erythro-2-Amino-1,2-diphenylethanol with Ester Enolates

Yukihiko Hashimoto,* Tsuneo Ogasawara, Minoru Hayashi, and Kazuhiko Saigo*

*Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan


Chiral imines, derived from (1S,2R)-2-methoxy-1,2-diphenylethyl-amine and aromatic aldehydes, reacted with ester enolates prepared from ketene silyl acetals and methyllithium to give β-lactams in good yields with high diastereoselectivity. This method provides a useful and simple route for the construction of optically active β-lactam skeletons.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1005 - 1013
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DOI: 10.3987/COM-99-S103
Ligand Effects on the Catalytic Asymmetric Autoinductive Aldol Reaction of 2-TMSOF (2-Trimethylsilyloxyfuran) with Aldehydes

Magali Szlosek, Jean-Christophe Jullian, Reynald Hocquemiller, and Bruno Figadère*

*Laboratoire de Pharmacognosie, associé au CNRS(BIOCIS), Université Paris-Sud, Faculté de Pharmacie, rue Jean-Baptiste Clément, 92296 Châtenay-Malabry Cedex, France


We report herein some recent progress in the reaction of 2-TMSOF (2-trimethylsilyloxyfuran) with achiral aldehydes in the presence of a new catalytic system (which does not use the expensive Binol catalyst) yielding the corresponding butenolides with good diastereomeric ratios (d.e. = 90 %) and moderate e.e.’s (50 %).

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1015 - 1020
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DOI: 10.3987/COM-99-S116
Synthesis of Polyaminoalkyl Substituted Conjugates of Pyrrolo[2,1-c][1,4]benzodiazepine Involving SNAr Reaction of 2-Nitro-5-fluorobenzoate Precursors

Kiyoshi Matsumoto,* Hirokazu Iida, and J. William Lown*

*Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan


A synthetic procedure is described for conjugating polyaminoalkyl groups to the pyrrolo[2,1-c][1,4]benzodiazepine pharmacophore in order to alter its characteristic DNA sequence binding preference. To this end SNAr reactions of 2-nitro-5-fluorobenzoate esters with different polyaminoalkyl side chains were examined and incorporated in the synthetic scheme.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1021 - 1024
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DOI: 10.3987/COM-99-S118
Oxidation of 1H-2-Benzoselenopyrans. Generation of Benzoselenophenes, Benzaldehydes, and Benzophenones

Kentaro Okuma,* Kazuki Kojima, Yuji Koga, and Kosei Shioji

*Department of Chemistry, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan


Oxidation of 1H-2-benzoselenopyrans bearing electron-withdrawing substituents gave benzoselenophenes, benzaldehydes, and benzophenone derivatives via the corresponding selenoxides followed by Pummerer and [3,3]sigmatropic rearrangements.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1025 - 1028
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DOI: 10.3987/COM-99-S119
Substituent Effects on the Stereochemical Course of Electrophile-initiated Tetrahydropyran-forming Reactions: A Possible Stereoelectronic Effect

David J. Hart,* Suzanne Patterson, and Alain Zakarian

*Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, U.S.A.


A series of 4-penten-1,3-diol derivatives were prepared and treated with phenylselenenyl chloride to provide tetrahydropyrans. The stereochemical course of the reactions is consistent with a chair-like transition state in which the oxygen substituent at the 3-position largely occupies an axial site. A structurally related 3-methyl-4-penten-1-ol derivative gave a major product consistent with a chair transition state in which the methyl group occupies an equatorial site.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1029 - 1032
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DOI: 10.3987/COM-99-S122
Kinetic Resolution of cis-3-Alkylcyclohexene Oxide by a Chiral Lithium Amide - An Application to a Synthesis of Both Enantiomers of Isomenthon -

Masatoshi Asami,* Shinsuke Sato, Kiyoshi Honda, and Seiichi Inoue

*Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan


Kinetic resolution of cis-3-alkylcyclohexene oxide (1) was examined using chiral lithium amide, lithium (S)-2-(pyrrolidin-1-yl)methylpyrrolidide (2). High ee (84Æ98% ee) of 1 was obtained by using 1.1-1.2 equiv of 2, while 6-alkyl-2-cyclohexenol (3) was obtained in moderate ee (60-68% ee) by using 0.5-0.75 equiv of 2. Both enantiomers of cis-2-isopropyl-5-methylcyclohexanone (isomenthone) were derived from (1S,2R,3R)-(+)-3-isopropylcyclohexene oxide (1b) or (1R,6R)-(-)-6-isopropyl-2-cyclohexenol (3b) in a few steps, respectively.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1033 - 1036
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DOI: 10.3987/COM-99-S124
Isolation and Structure of Kasarin, a Novel Azetinone Compound, Isolated from a Marine Microorganism

Kiyotake Suenaga, Sachiko Aoyama, Wang Xi, Hirokazu Arimoto, Kohji Yamaguchi, Kaoru Yamada, Tomoko Tsuji, Akihiro Yamada, and Daisuke Uemura*

*Department of Chmistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan


Kasarin (1), a novel azetinone compound, was isolated from a marine microorganism. The gross structure of kasarin was elucidated by spectroscopic analyses. Kasarin exhibited antibacterial activity and weak cytotoxicity.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1037 - 1040
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DOI: 10.3987/COM-99-S125
Scandium Triflate Catalyzed Formation of Benzothiazole from 2-Aminobenzenethiol and Formaldehyde in the Presence of Water

Takashi Itoh, Kazuhiro Nagata, Michiko Miyazaki, and Akio Ohsawa*

*School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan


In the presence of a catalytic amount of scandium triflate, 2-aminobenzenethiol and formaldehyde in water reacted to give an imine, followed by ring closure to afford a thiazoline, which was aromatized by oxygen or DDQ to give a high yield of benzothiazole.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1041 - 1045
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DOI: 10.3987/COM-99-S126
Optically Active Aldiminato Cobalt(II) Complex Catalyst for Enantioselective Hetero Diels-Alder Reaction

Tohru Yamada,* Satoko Kezuka, Tsuyoshi Mita, and Taketo Ikeno

*Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan


Among various aldiminato metal complexes, the optically active cobalt(II) complex efficiently catalyzed the enantioselective hetero Diels-Alder reaction of aromatic aldehydes with 1-methoxy-[3-(tert-butyldimethylsilyl)oxy]- 1,3-butadiene. In the presence of 0.5 mol% of the catalyst, the reaction smoothly proceeded and ortho substituents of the dienophiles that could chelate to the catalyst significantly accelerated the reaction to improve the chemical and optical yields.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1047 - 1056
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DOI: 10.3987/COM-99-S127
An ab initio Study on the Hydrogen Bond Energies of Nucleic Acid Basepairs: Adenine-Uracil Watson-Crick and Guanine-Uracil Wobble Basepairs

Shun-ichi Kawahara and Tadafumi Uchimaru*

*Department of Physical Chemistry, National Institute of Materials and Chemical Research, Agency of Industrial Science and Technology, MITI, Tsukuba Science City 305-8565, Japan


The hydrogen bond energies of adenine-uracil Watson-Crick and guanine-uracil wobble basepairs were evaluated using molecular orbital theory. The hydrogen bond energies were found to be almost the same for these two systems, thus uracil can distinguish adenine (A) and guanine (G) only when in combination with the backbone of a nucleotide duplex.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1057 - 1064
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DOI: 10.3987/COM-99-S130
Reactivity of Conjugated Phosphazenes Derived from Dehydroaspartic Esters with Acyl Halides. Synthesis of 5(4H)-Oxazolone

Francisco Palacios,* Marta Legido, Itziar Perez de Heredia, and Gloria Rubiales

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


The reactivity of N-vinylic phosphazenes derived from dehydroaspartic esters towards acyl halides is reported. Treatment of conjugated phosphazene with acyl halides led to the formation of N-acylated dehydroaspartic esters and alkenyl-5(4H) oxazolones. When the reaction was performed in the presence of diethylamine, 1-diethylamino-3,4-diethoxycarbonyl-2-aza-1,3-butadiene was obtained. Reaction of substituted 5(4H)-oxazolones with water, ethanol and amines gave N-acylated dehydroaspartic derivatives.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1065 - 1069
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DOI: 10.3987/COM-99-S133
Catalytic Asymmetrization of cis-2-Cyclopentene-1,4-diol. Highly Efficient and Practical Synthesis of (R)-4-Benzoyloxy-2-cyclopenten-1-one

Takeshi Oriyama* Takeshi Hosoya, and Tomohumi Sano

*Faculty of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan


Highly efficient, direct, and practical synthesis of (R)-4-benzoyloxy-2-cyclopenten-1-one, a chiral building block for various prostaglandins, with excellent ee was performed by the catalytic asymmetric acylation of cis-2-cyclopentene-1,4-diol, followed by oxidation with PDC.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1071 - 1074
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DOI: 10.3987/COM-99-S135
Modified Cyclization of Enantio-enriched α-Homoallyloxyalkyllithiums Generated by Sn-Li Transmetallation: Effects of Additives and Structural Requirement

Nobuyuki Komine, Katsuhiko Tomooka,* and Takeshi Nakai*

*Department of Applied Chemistry, Graduate School of Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan


The titled cyclization, when performed in the presence of lithium chloride, afforded an improved yield of the enantio-enriched 2,3-trans-disubstituted tetrahydrofuran derivative in high diastereoselectivity, whereas a similar cycization in the presence of zinc bromide gave the 2,3-cis isomer as the major product in lower enantiopurity.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1075 - 1078
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DOI: 10.3987/COM-99-S137
Two New Chlorine-containing Germacranolides, Eupaglehnins E And F from Eupatorium glehni

Motoo Tori,* Yoshiko Takeichi, Hiroe Kuga, Katsuyuki Nakashima, and Masakazu Sono

*Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihamabouji, Yamashiro-machi, Tokushima, 770-8514, Japan


Two new chlorine-containing germacrane-type sesquiterpenoids, eupaglehnins E and F, have been isolated from the MeOH extract of Eupatorium glehni (Compositae) and their structures have been determined on the basis of high resolution 2D NMR analyses.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1079 - 1082
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DOI: 10.3987/COM-99-S148
A Novel Synthesis of a 2,8-Dioxabicyclo[3.2.1]octane Skeleton from a 2,5-Dialkyltetrahydrofuran Derivative

Shunya Takahashi, Shinsuke Hirota, and Tadashi Nakata*

*RIKEN(The Institute of Physical and Chemical Research), Wako-shi, Saitama 351-0198, Japan


A unique method for the construction of 6,7-dihydroxy-2,8-dioxabicyclo[3.2.1]octane, a core component of zaragogic acids, was developed based on zinc acetate-mediated rearrangement reaction of a 2,5-dialkyltetrahydrofuran derivative having a 1'-monochlate on the C2-side chain.

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Communication | Special issue | Vol 52, No. 3, 2000, pp. 1083 - 1085
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DOI: 10.3987/COM-99-S150
Short Synthesis of (±)-Tacamonine by the Intramolecular Double Michael Reaction

Makoto Suzuki and Masataka Ihara*

*Departmenr of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aobayama, Sendai 980-8578, Japan


The racemate of tacamonine (1), an indole alkaloid of pseudovincamine type, was synthesised in short steps via the intramolecular double Michael reaction of the unsaturated amide (3).

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1087 - 1103
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DOI: 10.3987/COM-98-8235
Design and Syntheses of 2-Oxiranecarboxylate Derivatives and Their Hypoglycemic Activities

Sang-sup Jew,* Eun-kyung Kim, Sun-mi Je, Long-Xuan Zhao, Hyung-ook Kim, Hyeung-geun Park, Kwang-ho Ko, Won-ki Kim, Hwa-Jung Kim, Jae Hoon Cheong, and Eung-Seok Lee*

*College of Pharmacy, Seoul National University, Shillim-Dong, San 56-1, Kwanak-Gu, Seoul 151-741, Korea


A series of 2-oxiranecarboxylate derivatives were prepared as carnitine palmitoyl transferase I (CPT-I) inhibitors for the development of new antidiabetic agents. The syntheses and biological activities were reported. The most promising derivative (13b) showed 2.5 times more hypoglycemic activity and 2 times lower acute toxicity compared to Etomoxir (3).

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1105 - 1123
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DOI: 10.3987/COM-99-S85
Stereoselective Total Synthesis of Cephalosporolide D

Isamu Shiina,* Hidehiko Fujisawa, Toshihiro Ishii, and Yoshio Fukuda

*Department of Applied Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka 1-3, Shinjuku-ku, Tokyo 162-8601, Japan


An efficient method for the synthesis of (-)-cephalosporolide D is established via successive enantioselective aldol and effective 8-membered ring lactone forming reactions.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1125 - 1131
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DOI: 10.3987/COM-99-S87
Geminal Disilylmethylation of Dioxolanes with Silylmethyl Grignard Reagents

Yu-Tsai Hsieh and Tien-Yau Luh*

*Department of Chemistry, National Taiwan University, Roosevelt Road Section 4, Taipei 106, Taiwan, R.O.C.


Reactions of dioxolanes with excess Me3SiCH2MgCl in refluxing benzene yield the corresponding geminal disilylmethylation products in moderate to good yields. Intermediate alkoxy alcohol (11) was isolated. Similar reactions with ketals give the corresponding olefins and/or allylsilanes depending on the nature of the starting materials.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1133 - 1141
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DOI: 10.3987/COM-99-S112
The Preparation of Certain Nitrogen and Sulfur Containing Polycyclic Heterocycles by the Reaction of Arynes Possessing Charged Groups with α-Lithio-α-cyano-o-tolunitrile and α-Lithio-3-thienylacetonitrile

Anlai Wang, Hongming Zhang, and Edward R. Biehl*

*Department of Chemistry, Southern Methodist University, P.O. Box 750314, Dallas, TX 75275, U.S.A.


The synthesis of a wide variety of polycyclic heterocycles by the reaction of arynes or hetarynes possessing charged substituents with lithiated 3-thiopheneacetonitrile (22) or α-cyano-o-tolunitrile (2) is reported. Specific heterocycles prepared include: 9-aminonaphtho[2,3-b]thiophen-8-yl]methanol from 2,3-dehydrobenzyl oxide and 22; 5-amino-4-hydroxybenzo[g]isoquinoline-10-carbonitrile from 3,4-dehydropyridine-oxide and 2; 4-aza-2-oxodibenzo[cd,g]indole-6-carbonitrile from 2,3-dehydronicotinamide and 2; and 5-methyl- and 5-methoxy-2-oxo-1,2-dihydrodibenzo[cd,g]indole-2-carbonitrile from 4-methyl- and 4-methoxy-benzyne-3-carboylate, respectively and 2. Possible mechanisms for these reactions are discussed.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1143 - 1162
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DOI: 10.3987/COM-99-S113
Mannich Type Reactions of Acylhydrazones with Silyl Enolates for the Synthesis of β-Amino Ester, β-Amino Ketone, β-Lactam, Pyrazolidinone, and Pyrazolone Derivatives

Osamu Okitsu, Hidekazu Oyamada, Takayuki Furuta, and Shu Kobayashi*

*Graduate School of Pharmaceutical Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan


In the presence of a catalytic amount of a rare earth triflate, acylhydrazones reacted with silyl enolates to afford the corresponding β-N'-acylhydrazino esters in high yields. A three-component reaction of an aldehyde, an acyihydrazine, and a silyl enolate was also performed successfully. The hydrazino esters thus obtained were readily converted to β-amino ester, β-amino ketone, β-lactam, pyrazolidinone, and pyrazolinone derivatives.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1163 - 1169
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DOI: 10.3987/COM-99-S114
Synthesis of 3-Trifluoromethyl-3-aryldiazirines for Photoaffinity-labeling Probes and Their Labeling Ability

Chikanori Morita, Kimiko Hashimoto, Toshikatsu Okuno, and Haruhisa Shirahama*

*School of Science, Kwansei Gakuin University, Uegahara, Nishinomiya 662-8501, Japan


Photoaffinity-labeling probes of aryldiazirine derivatives with three substituents (diazirine, nitro, and alkyl or alkoxy) on C1, C2, and C4 of the benzene nucleus were synthesized and their labeling abilities were tested. Among the synthetic compounds (4, 5, and 12), only 12 was appropriate for the photoaffinity probe.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1171 - 1189
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DOI: 10.3987/COM-99-S115
Preparation of Sn-, Ge-, and Si-Heterocycles from Zirconacycles

Yasuyuki Ura, Yanzhong Li, Fu-Yu Tsai, Kiyohiko Nakajima, Martin Kotora, and Tamotsu Takahashi*

*Catalysis Research Center and Graduate School of Pharmaceutical Sciences, Hokkaido University, and CREST, Science and Technology Corporation (JST), Sapporo 060-0811, Japan


Stannacycles such as stannacyclopentanes, stannacyclopentenes and stanacyclopentadienes were prepared from the corresponding zirconacycles. The effect of addition of CuCl on the reaction of zirconacycles with tin halides is remarkable. In the case of germanium and silicon halides, the remarkable effect of CuCl addition was not observed. Symmetrical or unsymmetrical germa- and silacycles were prepared by the reaction of silicon or germanium halides with dilithio compounds prepared from the corresponding zirconacycles. Several heterocyclic compounds containing two metalloatoms were also prepared.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1191 - 1201
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DOI: 10.3987/COM-99-S117
An Asymmetrical Total Synthesis of a Potent Immunosuppressant, Mycestericins D and F, through an Aldol Reaction Using L-Threonine Aldolase

Kiyoharu Nishide, Kayoko Shibata, Tetsuro Fujita, Tetsuya Kajimoto, Chi-Huey Wong, and Manabu Node*

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


L-Threonine aldolase from Candida humicola catalyzed the aldol reaction of 4-benzyloxybutanal (1) with glycine to give β-hydroxy-α-amino acids (2e,t), whose erythro / threo ratio was controlled by using either kinetic or thermodynamic conditions. The erythro derivative (4e) was effectively converted to mycestericins D and F via a stereoselective hydroxymethylation of oxazoline derivative (6) as the key step.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1203 - 1206
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DOI: 10.3987/COM-99-S123
Perchloric Acid in 1,4-Dioxane and Perfluorooctanesulfonic Acid as Practical Catalysts for the Stereoselective Glycosylation of 1-O-Acetylglycosides

Yasuo Yokoyama, Takeshi Hanamoto, Xiu Lan Jin, Yong Zhi Jin, and Junji Inanaga*

*Institute for Fundamental Research of Organic Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan


A perchioric acid solution in 1,4-dioxane and perfluorooctanesulfonic acid was found to be practical catalysts for the stereoselective glycosylation of 1-O-acetyiglycosides. Either the α- or β-anomer of the disaccharide, methyl 2,3,4-tri-O-benzyl-6-O-(2,3,5-tri-O-benzyl-D-ribofuranosyl)-α-D-glucopyranoside, was synthesized with complete stereoselectivities simply by changing the solvent. Epimerization of the kinetic product can effectively be suppressed in ether by the excess use of the polyoxygenated substrates.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1207 - 1214
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DOI: 10.3987/COM-99-S129
Selective Reduction of the 7-Oxo Group in Pyrido[2,3-d]pyrimidine-4,7-diones: A New Synthetic Approach to 5,10-Dideazatetrahydrofolic Acid (DDATHF)

José I. Borrell,* Jordi Teixidó, Josep Lluís Matallana, Blanca Martínez-Teipel, and Esther Couceiro

*Departament de Química Orgànica, Institut Quimic de Sarrià, Universitat Ramon Llull, E-08017 Barcelona, Spain


A selective reduction of the carbonyl group at C7 with borane in THF is accomplished for 2,4-diamino-7-oxo and 2-amino-4,7-dioxo substituted pyridopyrimidines (7a-c) and (13a-c) respectively, the ester group remaining unaltered in both cases. The synthesis of 21c allows a new synthetic approach to 5,10-dideazatetrahydrofolic acid (DDATHF, 1) because it is a common intermediate in two procedures that afford the aforementioned antifolate.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1215 - 1230
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DOI: 10.3987/COM-99-S134
Oxidative Cycloaddition of Molecules with Multiple Thiophene Cores

Thies Thiemann,* Yuanqiang Li, Carolin Thiemann, Tsuyoshi Sawada, Daisuke Ohira, Masashi Tashiro, and Shuntaro Mataka*

*Instituete of Advanced Material Study, Kyushu University, 6-1, Kasuga-koen, Kasuga-shi, Fukuoka 816-0811, Japan


The oxidative cycloaddition of molecules with multiple thienyl-units to alkynes and alkenes is described. The reaction proceeds at room temperature. Yields can be increased upon the use of BF3·Et2O. Intermediates of the reaction are thiophene-S-oxides. An examplary isolation of a thiophene-S-oxide (16) in this series and its subsequent cycloaddition are shown. In the case of the oxidative cycloaddition of the thiophenes with alkenes 7-thiabicyclo[2.2.1]heptene-S-oxides (cf., 9) are formed. An X-Ray crystal structural analysis of 9a-H indicates the cycloaddition to be stereoselective (syn-endo). The SO-bridge in these bicyclic subunits could be extruded both thermally and oxidatively under FTC-conditions at room temperature. The products are novel orthocyclophanes.

Paper | Special issue | Vol 52, No. 3, 2000, pp. 1231 - 1239
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DOI: 10.3987/COM-99-S136
The Synthesis of Bicyclic Piperazine-2-carboxylic Acids from L-Proline

Stephen Hanessian* and Raman Sharma

*Department of Chemistry, Université de Montréal, Montréal, Que’bec H3C 3J7, Canada


The stereocontrolled synthesis of two diastereomeric bicyclic piperazine-2-carboxylic acids from L-proline is described.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1241 - 1249
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DOI: 10.3987/COM-99-S138
Development of a Method for the Synthesis of α-Substituted α,β-Unsaturated Lactones Based on Stille-Type Pd-catalyzed Carbonylation of (Z)-ω-Iodoalkenols. An Efficient and Selective Synthesis of (+)-Hamabiwa-lactone B

Baiqiao Liao and Ei-ichi Negishi*

*Herbert C. Brown Laboratory of Chemistry, Purdue University, West Lafayette, Indiana 47907, U.S.A.


Pd-Catalyzed carbonylative lactonization of (Z)-ω-iodoalkenols can be applied to synthesize α,β-unsaturated lactones containing an alkenyl or alkynyl substituent in the α position, providing a generally superior alternative to recently developed methods involving Pd-catalyzed α-substitution of α-stannyl esters, as exemplified by a highly expeditious synthesis of (+)-hamabiwalactone B.

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Paper | Special issue | Vol 52, No. 3, 2000, pp. 1251 - 1260
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DOI: 10.3987/COM-99-S139
A Formal Synthesis of (-)-Dehydrochamaecynenol. Asymmetric Synthesis of an Advanced Key Intermediate

Hsing-Jang Liu* and Daqing Sun

*Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada


Keto ester (2), which served as an advanced intermediate in the total synthesis of (±)-dehydrochamaecynenol (1), has been prepared in optically active form.

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45 data found. 1 - 30 listed Next Last