Special Issue

Gilbert Stork's Special Issues, Vol. 25, No. 1, 1987

96 data found. 31 - 60 listedFirst Previous Next Last
Communication | Special issue | Vol 25, No. 1, 1987, pp. 155 - 156
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DOI: 10.3987/S-1987-01-0155
A Synthesis of (±)-1- and (±)-3-Hydroxy-(C)-homoaporphines via meta-Bridged Aromatic Lactams

Osamu Hoshino, Hiromichi Ogasawara, Atsuo Takahashi, and Bunsuke Umezawa

*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278-8510, Japan

Abstract

The title (C)-homoaporphines (4) were synthesized starting with meta-bridged aromatic lactams (2) readily obtained by photolysis of phenolic N-phenethylbromophenylpropionamides (1).

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 157 - 165
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DOI: 10.3987/S-1987-01-0157
Synthesis of Vinca Alkaloids and Related Compounds. XXXIII. Formation of a New Ring System via Addition of Methyl Acrylate to Indoloquinolozone Derivatives

Lajos Szabó, Pál Kolonits, György Kalaus, Alajos Kálmán, László Párkányi, and Csaba Szántay

*Institute for Organic Chemistry, Technical University Budapest, H-1521 Budapest, P.O. Box 91Gellért tér 4, Hungary

Abstract

While acrylic acid esters alkylate enamine 4b with free indole NH group at position C-1, indole N-Me containing analogues react in a different way. The structure of the new products (1a and 2 ) has been elucidated by X-ray crystallography.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 167 - 173
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DOI: 10.3987/S-1987-01-0167
Studies on the Total Synthesis of Granaticin: Synthesis of (±)-7-Deoxygranaticin 12-O-Methyl Ether from Chrysazin

Keiichi Nomura, Kozo Hori, Makoto Ishizuka, and Eiichi Yoshii

*Faculty of Pharmaceutical Sciences, , Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

The title compound (27) has been synthesized starting with chrysazin (1,8-dihydroxyanthraquinone) via 10-methoxy-8-(methoxy)methoxy-1-anthracenone (9). The strategy involves a stepwise and srereoselertive construction of the oxabicycle and pyranolactone systems upon 9.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 175 - 178
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DOI: 10.3987/S-1987-01-0175
An Alternate Synthesis of Furoventalene Using an Extension of Hagiwara‘s Construction of the 3-Methylfuran Moiety

Ricardo Castanedo, Carlos Bernardo Zetina, and Luis Angel Maldonado

*Div. Estudios de Posgrado, Facultad de Química, Universidad Nacinal Autónoma, Circuito Exterior, Ciudad Universitaria, Coyoacán 04510, Mexico

Abstract

A new total synthesis of furoventalene 5 is reported. Key steps in the sequence are the Birch reduction-homoprenylation in situ of aromatic carboxylic acids precursors, construction of the 3-methylfuran moiety by Hagiwara’s method and decarboxylative aromatization of an appropriate intermediate.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 179 - 182
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DOI: 10.3987/S-1987-01-0179
2-Cyano-6-methoxytetrahydropyran, a Useful protected Cyanohydrin for 2-Substituted Cyclohexenone Synthesis

Georgina Cecilia Laredo and Luis Angel Maldonado

*Div. Estudios de Posgrado, Facultad de Química, Universidad Nacinal Autónoma, Circuito Exterior, Ciudad Universitaria, Coyoacán 04510, Mexico

Abstract

The title compound 1, easily prepared from commercially available glutaraldehyde, is a protected cyanohydrin useful as synthon for the preparation of 2-substituted cyclohexenones.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 183 - 188
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DOI: 10.3987/S-1987-01-0183
A New Synthesis of 1,3-Thiazine Derivatives Having a Dithiolane Ring and Their Reductive Clevage with Sodium Cyanoborohydride

Renji Okazaki, Masafumi Unno, and Naoki Inamoto

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

Abstract

Some new 1,3-thiazines containing 1,3-dithiolane were synthesized by [4 + 2] cycloaddition of 2-thioacylimino-1,3- dithiolanes with methyl vinyl ketone and allowed to react with sodium cyanoborohydride to give unusual reduction product with a loss of the dithiolane ring together with normal C=N reduction products.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 189 - 192
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DOI: 10.3987/S-1987-01-0189
Photochemical Cyclobutanone Expansions

Michael C. Pirrung and Carl V. DeAmicis

*Department of Chemistry, Stanford University, 735 Dolores Street, Stanford, CA 94305-5080, U.S.A.

Abstract

As a model for a new approach to bond formation at anomeric carbons, the addition of various heteroatom derivatives to oxacarbenes generated by the photochemical ring expansion of cyclobutanones has been examined. Practical procedures have been developed for the insertion of such carbenes into heteroatom-H bonds from alcohols, thiols, and amines using minimal excess trapping reagent.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 193 - 200
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DOI: 10.3987/S-1987-01-0193
Diazapolycyclic Compounds. XXVI. Diazaquinone Adducts from Isoprenoid Compounds

Fernando Gómez Gontreras, Manuel Lora-Tamayo, and Ana María Sanz

*Instituto de Química Orgánica General, C. S. I. C., Calle Juan de Cierva, 3, 28006 Madrid, Spain

Abstract

Diazaquinones such as phthalazine- and benzo(g)-phthalazine-1,4-dione react with isoprenoid compounds to give 4+2 diazapolycyclic adducts. Treatment with β-myrcene, alloocimene, neoalloocimene or ergocalciferol affords the expected cycloaddition products in good yields, whereas no reaction is found with β-ionone or retinol acetate. Some side-chain derivatives of these adducts have also been prepared.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 201 - 204
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DOI: 10.3987/S-1987-01-0201
A Photochemistry of 1-(1-Phenylvinyl)-3,4-dihydroisoquinoline

Yoshiro Hirai, Hiroyuki Egawa, Yuko Wakui, and Takao Yamazaki

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

Irradiation of the 1-(1-phenylviny1)-3,4-dihydroisoquinoline (3) in benzene in the presence of xanthone gave the spirobenzylisoquinoline (4) in low yield. On the other hand irradiation of 3-hydrochloride in alcohol solvent (methanol, ethanol, and iso-propanol) afforded the hydroxyalkylated product, (10), (13), and (14) in moderate yield, respectively.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 205 - 211
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DOI: 10.3987/S-1987-01-0205
The Tandem Michael-aldol Reaction Catalyzed by Trityl Perchlorate

Teruaki Mukaiyama and Shu Kobayashi

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

Abstract

In the presence of a catalytic amount of trityl perchlorate, the tandem reaction of conjugate addition of silyl enol ethers to α,β-unsaturated ketones, and the sequential aldol reaction with aldehydes is carried out smoothly to afford γ-acylsubstituted δ-hydroxy ketone derivatives stereoselectively in high yields. The ketones thus obtained are easily converted to tetrahydropyrane or δ-valerolactone derivatives.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 213 - 216
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DOI: 10.3987/S-1987-01-0213
Preparation of α-Arylsulfonyl Lactams

Jon D. Stewart and Harold W. Pinnick

*Department of Chemistry, Bucknell University, Lewisburg, PA 17837, U.S.A.

Abstract

Lactam enolates are efficiently converted into α-arylsulfonyl lactams by aryl sulfonate esters.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 217 - 220
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DOI: 10.3987/S-1987-01-0217
Formation of 3,3-Disubstituted Indolenines from Intramolecular Nitrene Reaction with Isoquinoline and Naphthalene Moieties

R. Bryan Miller, Sundeep Dugar, and James R. Epperson

*Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616-5295, U.S.A.

Abstract

Thermolysis of azides 2,7, and 14 gave nitrenes which reacted intramolecularly with isoquinoline and naphthalene moieties t o produce 3,3- disubstituted indolenines 3,8, and 15, respectively, as the major products and carbazole derivatives 1,9, and 16, respectively, as the minor products.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 221 - 227
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DOI: 10.3987/S-1987-01-0221
Synthesis of a Novel Carbapenem-potassium (5R,6R)-1,1-Difuluoro-2-phenyl-6-(1R-hydroxyethyl)-carbapen-2-em-3-carbozylate. The Use of a New N-Protecting Group in β-Lactam Synthesis

Nalini V. Shah and Lovji D. Cama

*Merck Sharp and Dohme Research Laboratories, Rahway, NJ 07065, U.S.A.

Abstract

A synthesis of a novel 1.1-difluorocarbapenem (1), utilizing a new N- protecting group for the 1-position of 2-azetidinones is described.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 229 - 233
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DOI: 10.3987/S-1987-01-0229
Reactions of Quinoline and 4-Chloroquinoline 1-Oxides with Phenoxyacetonitrile, Chloromethylphenylsulfone, and Methylthiomethyl-p-tolylsulfone

Masatomo Hamana, Yasuo Fujimura, and Terushi Haradahira

*Central Research Laboratories, Chugai Pharmaceutical Company, Ltd., Takada 3-41-8, Toshima-ku, Tokyo 171, Japan

Abstract

Quinoline and 4-chloraquinoline 1-oxides react with phenoxyacetonitrile (1) and chloromethylphenylsulfone (3) in KOHDMSO and in t-BuOK-THF to give the respective vicarious nucleophilic substitution products, 2-cyanomethyl- (2a and 2b) and 2- phenylsulfonylmethylquinoline 1-oxides (4a and 4b). The reactions with methylthiomethyl-p-tolylsulfone (5) afford not only the vicarious nucleophilic substitution products(6a and 6b) but also the products by means of hydride elimination(7a and 7b).

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 235 - 239
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DOI: 10.3987/S-1987-01-0235
Reactions of Quinoline 1-Oxide with Cyanoacetic Acid Derivatives Bearing Leaving Groups

Masatomo Hamana, Yasuo Fujimura, and Yoshiharu Nawata

*Central Research Laboratories, Chugai Pharmaceutical Company, Ltd., Takada 3-41-8, Toshima-ku, Tokyo 171, Japan

Abstract

Quinoline 1-oxide reacts with bromocyanoacetic acid derivative (1a, 1b and 2a) in the presence of acetic anhydride to afford 2-substituted quinolines (3a, 3b and 6) through the vicarious nucleophilic substitution and the subsequent deoxygenation. From reactions with phenylthiocyanoacetic acid derivatives (1c, 1d and 2b), the deoxygenated α-substitution products (8c and 8d) are farmed in addition to 3a, 3b and 6.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 241 - 244
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DOI: 10.3987/S-1987-01-0241
Asymmetric Synthesis of 4-Acetoxy-3-hydroxyethylazetidin-2-one, a Key Intermediate for the Preparation of Penem and Carbapenem Antibiotics

Tetsuji Kametani, Shin-Der Chu, and Toshio Honda

*Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan

Abstract

Asymmetric synthesis of 4-acetoxy-3-hydroxyethylazetidin-2-one with desired stereochemistry has been achieved by employing [3+2]dipolar cycloaddition of a chiral nitrone with benzyl crotonate as a key reaction.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 245 - 249
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DOI: 10.3987/S-1987-01-0245
Studies towards the Total Synthesis of Mexicanolide. Stereoselective Construction of the CD Ring Segment for a Convergent Approach

Hsing-Jang Liu and Teofilo Dieck-Abularach

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

Abstract

The CD ring segment 18 required for a convergent approach towards the total synthesis of the limonoid mexicanolide (3) has been prepared in a highly stereoselective manner.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 251 - 258
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DOI: 10.3987/S-1987-01-0251
Quinuclidine·boranes as Intermediates in Formation and Isolation of Functionalized Quinuclidine Systems

Philip L. Stotter, Martin D. Friedman, Gordon O. Dorsey, Robert W. Shiely, Robert F. Williams, and David E. Minter

*Division of Earth and Physical Science, The University of Texas at San Antonio, San Antonio, Texas 78285, U.S.A.

Abstract

Stable N-borane complexes of quinuclidine systems are useful both as N-protected intermediates (in alkylation and hydroboration / oxidation reactions) and as derivatives which facilitete isolation / purification and subsequent characterization. Deprotection is readily effected using acidic oxidation of hydride.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 259 - 262
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DOI: 10.3987/S-1987-01-0259
Facile Preparation of Two 5-(α-Acetoxyethyl)-3-quinuclidinones via Intramolecular Functionalization

Philip L. Stotter, Kenneth A. Hill, and Martin D. Friedman

*Division of Earth and Physical Science, The University of Texas at San Antonio, San Antonio, Texas 78285, U.S.A.

Abstract

Two title compounds with three adjacent chiral centers have been prepared as diastereomerically-pure racemates of known stereochemistry, suitable for use as synthetic intermediates in Cinchona alkaloid synthesis. Stereochemical control of C-4 in the quinuclidine skeleton was established using intramolecular attack by the C-3 substituent of stereoisomerically-pure threo or erythro 3-(α-hydroxyethyl) quinuclidine via Barton oxidation.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 263 - 270
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DOI: 10.3987/S-1987-01-0263
General Methodology for cis-Hydroisoquinoline Synthesis. 3. A Sixteen Step Synthesis of Reserpine

Paul A. Wender, John M. Schaus, and Alan W. White

*Department of Chemistry, Stanford University, 735 Dolores Street, Stanford, CA 94305-5080, U.S.A.

Abstract

A concise synthesis of reserpine is described based on a Diels-Alder cycloaddition, Cope rearrangement sequence for hydroisoquinoline synthesis and on a new procedure for regulating stereochemistry at C-18.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 271 - 275
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DOI: 10.3987/S-1987-01-0271
A Stereospecific Synthesis of (±)-Perforenone

George Majetich and Clay Ringold

*The School of Chemical Science, Department of Chemsitry, The University of Georgia, Athens, Georgia 30602, U.S.A.

Abstract

The total synthesis of (±)-perforenone is reported featuring an intramolecular Sakurai reaction to construct the bicyclic skeleton.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 277 - 281
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DOI: 10.3987/S-1987-01-0277
Application of Allylsilanes in a Regiocontrolled [3+2] Annulation Route to Substituted Isoxazoles

Rick L. Danheiser and David A. Becker

*Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, U.S.A.

Abstract

Allenylsilanes react with nitrosonium tetrafluoroborate in acetonitrile at -30°C to provide 4-trialkylsilylisoxazole derivatives, which undergo in situ protodesilylation upon addition of water and heatinq to 70°C.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 283 - 286
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DOI: 10.3987/S-1987-01-0283
Studies towards the Total Synthesis of Strychnine (I)

Martha L. Quesada, Deukjoon Kim, Soon Kil Ahn, Nak Shin Jeong, Yun Hwang, Moohi Yoo Kim, and Joon Wan Kim

*College of Pharmacy, Seoul National University, Shillim-Dong, San 56-1, Kwanak-Gu, Seoul 151-742 , Korea

Abstract

A stereoselective synthesis of a potential synthetic intermediate 12 for the synthesis of Strychnine is described, wherein a series of Michael reactions are key steps.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 287 - 290
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DOI: 10.3987/S-1987-01-0287
Photo-induced Electron-transfer Oxidation of Nicotine

Shuzo Yamada, Toshiaki Sakai, and Mamoru Ohashi

*Department of Maerial Science, The University of Electro-Communications, 1-5-1, Chofugaoka, Chofu, Tokyo 182-0021, Japan

Abstract

Irradiation of nicotine in acetonitrile in the presence of Ti02 or 9,10-dicyanoanthracene under oxygen with a 100 W high pressure mercury lamp gave nicotyrine, cotinine, and dehydronornicotine. A reaction mechanism leading to these products through nicotine radical cation and superoxide anion is proposed.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 291 - 295
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DOI: 10.3987/S-1987-01-0291
Kinetic and Termadynamic Enolization of 3-Pyranones

David J. Goldsmith, Chalotte M. Dicknson, and Arthur J. Lewis

*Department of Chemistry, Emory University, 1521 Pierce Drive Atlanta, Georgia 30322, U.S.A.

Abstract

Kinetic enolization of 3-pyranones is favored toward the a-position away from the heterocyclic oxygen. This preference is even more marked under conditions of thermcdynamic enol acetate and enolate formation.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 297 - 300
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DOI: 10.3987/S-1987-01-0297
Preparation of 2,3,4,5-tetrahydropyridines from 5-Alkynylamines under the Catalytic Action of Au(III)

Yukitoshi Fukuda, Kiitiro Utimoto, and Hitoshi Nozaki

*Faculty of Engineering, Kyoto University, Yoshida, Sakyou-ku, Kyoto 606-8501, Japan

Abstract

Intramoleculr addition of amine to acetylene moiety produces 2,3,4,5-tetrahydropyridines from 5-alkynyl-amines under catalytic action of Au (111) .

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 301 - 304
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DOI: 10.3987/S-1987-01-0301
Polonovski Reactions of Mitosane Derivatives

Samuel Danishefsky and Gregg B. Feigelson

*Department of Chemistry, Yale University, P.O. Box 6666, New Haven, Connecticut 06511, U.S.A.

Abstract

Reaction of N-oxide 4 with acetic anhydride oxidizes carbons 3, 11 and 9a, thus providing a route to novel mitomycin congeners.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 305 - 313
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DOI: 10.3987/S-1987-01-0305
Synthesis Studies of Periplanone A, a Sex Pheromone of Periplaneta americana

Timothy L. Macdonald, Claire M. Delahunty, and J. Scott Sawyer

*Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, U.S.A.

Abstract

Germacratrienone oxide 4 is proposed to be periplanone A, the minor component of the sex pheromone of Periplaneta americana, and to undergo transannular cyclization to oxamethylene-bridged hydroazulenone 5, which had previously been postulated without stereochemical definition to be the natural pheromone.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 315 - 320
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DOI: 10.3987/S-1987-01-0315
Michael Addition Reactions of Unsaturated Esters with Lithium Enolates Derived from Vinylogous Urethanes

Richard Schlessinger, Peter Lin, Michael Poss, and James Springer

*Department of Chemistry, University of Rochester, Rochester, NY 14627, U.S.A.

Abstract

The lithium enolate 1 of vinylogous urethane 2 undergoes highly diastereoselective conjugate addition reactions with unsaturated esters. The ester enolates aristing from conjugate addition can be methylated with high diastereoselectivity.

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Communication | Special issue | Vol 25, No. 1, 1987, pp. 321 - 327
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DOI: 10.3987/S-1987-01-0321
Stereochemical Studies of 1-Oxacephams by Means of NMR Spectroscopy. A Useful Shift Rule for Determination of the 3-Substituent Configration

Tsutomu Aoki, Wataru Nagata, Yohko Yoshimura, Junko Nishikawa, and Kazuo Tori

*Shionogi Research Laboratories, Shionogi & Co. Ltd., Fukushima-ku, Osaka 553-0002, Japan

Abstract

Conformation of 1-oxacephams with a carbon-substituent at C3 was determined to be in a half chair by nmr spectroscopy. A useful shift rule for determination of the C3 configuration in both 1-oxacepham and cepham derivatives has been established an the basis of difference in H-3’ chemical shifts between the methyl and benzhydryl esters. This rule, propasedly called “the benzhydryl shift rule,” has been proved to be generally applicable.

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