Regular Issue

Vol. 23, No. 8, 1985

38 data found. 1 - 30 listed Next Last
Communication | Regular issue | Vol 23, No. 8, 1985, pp.1863-1867
Published online:
DOI: 10.3987/R-1985-08-1863
Partial Syntheis of Dihydroisothysanolactone, and 13C-NMR Study of Thysanolactone

Norio Aimi,* Kazuhiro Kawada, Hiroshi Murakami, Yoshitaka Fukumasu, and Shin-ichiro Sakai

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

Abstract

Dihydroisothysanolactone (14) which has the diastereomeric construction of the bridged ring system of the A ring of the novel triterpene, thysanolactone (1), has been partially synthesized from an easily available triterpene, hydroxyhopanone (3). 13C-NMR assignment of all carbons of thysanolactone (1) has been made by the help of the reference compounds including the above newly prepared unnatural congener.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1869-1872
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DOI: 10.3987/R-1985-08-1869
Structure and Stereochemistry of 4-Deacetoxy-10-epi-olguine, a New δ-Lactone from Hyptis oblongifolia Bentham (Labiatae)

Guillermo Delgado, Rogelio Pereda-Miranda, and Alfonso Romo de Vivar*

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

Abstract

A minor secondary metabolite, 4-deacetoxy-10-epi-olguine, has been isolated from the aerial parts of Hyptis oblongifolia (Labiatae). Its structure has been elucidated as that represented by formula 1, based on spectral and crystallographic evidence.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1873-1879
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DOI: 10.3987/R-1985-08-1873
Carbon-carbon Bond Forming Reaction of Bis(chloromethyl)sulfone with Carbonyl Compounds: General Route to Aromatic 2-Chlorovinyl Compounds and α-Hydroxyaldehydes

Enkou Nagashima, Kunio Suzuki, Motoaki Ishikawa, and Minoru Sekiya*

*Shizuoka College of Pharmacy, 2-2-1, Oshika, Shizuoka-shi, 442 Shizuoka, Japan

Abstract

Bis(chloromethyl)sulfone (1) has been proved to be a useful reagent for the synthesis of aromatic 2-chlorovinyl compounds (4) from aromatic aldehydes and of α-hydroxyaldehydes (5) from aliphatic carbonyl compounds with one carbon prolongation. The sec-butyllithium-aided reaction of 1 with aromatic aldehydes gives 1,3-oxathiolane-3,3-dioxides (2) which are converted to 4 in good yields by thermolysis. On the other hand, the sodium hydride-aided reaction of 1 with aliphatic carbonyl compounds is favorable to the formation of chloromethylsulfonyloxiranes (3). Titanium tetrachloride has been found to be an efficient reagent for hydrolysis of 3 to 5.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1881-1884
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DOI: 10.3987/R-1985-08-1881
A Versatile One-pot Synthesis of Symmetrical N-Tosylazamacrocycles

Sebastiano Pappalardo,* Francesco Bottino, Michele Di Grazia, Paolo Finocchiaro, and Antonino Mamo

*Dipartimento di Scienze Farmaceutiche , Università di Catania, Viale A. Doria 6, 95125 Catania, Italy

Abstract

A variety of title compounds (azacrown ethers, pyridino-azacrown analogues and azacyclophanes) have been synthesized in moderate to good yield by coupling appropriate bis(halomethyl) or bis(tosylate ester) precursors with tosylamide monosodium salt. A revised mechanism is proposed.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1885-1888
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DOI: 10.3987/R-1985-08-1885
Synthesis of Vinca Alkaloids and Related Compounds XXIV. A New Rearrangement of the Isoquinuclidine Skeleton

Csaba Szántay,* Tibor Keve, Hedvig Bölcskei, Gábor Megyeri, and Eszter Gács-Baitz

*Central Research Institute for Chemistry, Hungarian Academy of Sciences, H-1025 Budapest, Pusztaszeri ut 59-67, P.O.Box 17, Hungary

Abstract

A new rearrangement of the isoquinuclidine skeleton under solvolytic conditions was observed. A pentacyclic intermediate was isolated and its structure elucidated.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1889-1892
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DOI: 10.3987/R-1985-08-1889
Synthetic Studies on Carbapenem Antibiotics from Penicillins. V. A Stereospecific Preparation of 4-Allylazetidinones

Matsuhiko Aratani, Hideo Hirai, Kozo Sawada, and Masashi Hashimoto*

*Fujisawa Pharmaceutical Co. Ltd., 2-1-6 Kashima, Yodogawa-ku, Osaka 532, Japan

Abstract

A stereospecific preparation of chiral 4-allylazetidinones 3, key intermediates for the synthesis of the carbapenem antibiotics, has been achieved in good yields by reaction of 4-acetoxyazetidinones 2 with allylsilanes in the apresence of TMSOTf.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1893-1896
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DOI: 10.3987/R-1985-08-1893
The Revised Structure of the Thermal Rearrangement Product of 4-Benzylideneamino-3-methyl-5-styrylisoxazole

Andreina Corsico Coda, Giovanni Desimoni,* and Alessandro Coda

*Dipartamento di Chimica Organica, Università di Pavia, V. le Taramelli 10, 27100 Pavia, Italy

Abstract

It had been claimed that the thermal rearrangement of 4-benzylideneamino-3-methyl-5-styrylisoxazol gave an isoxazolo-pyridine. This product was reinvestigated and shown to be 4-cinnamoyl-5-methyl-2-phenylimidazole, confirmed by X-ray analysis. A mechanism of formation is here proposed, involving the cleavage of the isoxazole N-O bond.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1897-1900
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DOI: 10.3987/R-1985-08-1897
Synthesis of N-Alkylisothiazolidines

Haruo Matsuyama,* Akira Izuoka, and Mishio Kobayashi

*Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan

Abstract

N-Alkylisothiazolidines were prepared by [2,3]-sigmatropic rearrangement of allyl 3-alkylaminopropyl sulfoxides to the sulfenates, followed by intramolecular thiophilic substitution of N-alkylamino moieties.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1901-1905
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DOI: 10.3987/R-1985-08-1901
Synthesis of C(3)-Alkyl Cephems

Douglas O. Spry* and Anita R. Bhala

*Lilly Reserach Laboratories, Lilly Corporate Center, Eli Lilly & Company, Indianapolis, IN 46285-4813, U.S.A.

Abstract

C(3)-n-Butyl and n-hexyl cephems have been prepared by the conjugate addition of the appropriate organocuprate to the C(3)-chloro and C(3)-vinyl cephem.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1907-1910
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DOI: 10.3987/R-1985-08-1907
Regiochemistry of Thermal Extrusion of Sulfur from 2,6-Diaryl-1,4-dithiins Yielding 2,5- and 3,4-Diarylthiophenes

Juzo Nakayama,* Masahiro Shimomura, Michiko Iwamoto, and Masamatsu Hoshino

*Department of Chemistry, Faculty of Science, Saitama University, Saitama, Saitama 338-8570, Japan

Abstract

The predominant formation of 2,5-diarylthiophenes over the 3,4-diaryl isomers by thermolyses of a series of 2,6-diaryl-1,4-dithiins 3,4-diaryl supports that this sulfur extrusion reaction proceeds by the mechanism involving the valence isomerization to thiocarbonyl ylide intermediate possessing a thiirane structure in the rate-determining step.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1911-1913
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DOI: 10.3987/R-1985-08-1911
Aromatic Versions of Claisen Rearrangement of Lactonic Silyl Enolates — A Novel to Furanosesquiterpene Framework

Hideo Nemoto, Eiki Shitara, Keiichiro Fukumoto,* and Tetsuji Kametani

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

Abstract

A new route to the decalin systems (14) and (15) is described. The key step for this synthesis is the Claisen rearrangement of furfuryl lactonic silyl enolates (8) and (9) derived from the furfuryl lactones (6) and (7), respectively.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1915-1919
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DOI: 10.3987/R-1985-08-1915
Synthesis of Carbaoenems with a RXCH2-Substituent in the 3-Position

Johannes G. de Vries,* Gerhard Sigmund, and Georg Vorisek

*Sandoz Forschungsinstitut, 1235 Wien, Brunnerstraße 59, Austria

Abstract

Carbapenems 6 were prepared by reacting mercaptans with bromoketone 3 followed by a Wittig sequence, or better through advanced intermediate 9. The carbapenem carboxylateas were chemically unstable; stability was not improved by changing the oxidation state of sulfur.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1921-1923
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DOI: 10.3987/R-1985-08-1921
Amyris of Jamaica. New Coumarins from Amyris elemifera L. (Rutaceae)

Saleela Philip and Basil A. Burke*

*Department of Chemistry, Mona Campus, University of the West Indies, Mona, Kingston 7, Jamaica

Abstract

The isolation of elemiferone, elemiferone monoacetate and elemiferone diacetate constitutes further evidence for the use of 3-(3’,3’-dimethylallyl)-coumarins as taxonomic markers for the genus Amyris.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1925-1928
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DOI: 10.3987/R-1985-08-1925
Total Synthesis of Ergot Alkaloid (±)-Fumigaclavine B

Toshiko Kiguchi, Chiyomi Hashimoto, and Ichiya Ninomiya*

*Kobe Women’s College of Pharmacy, Motoyamakita, Higashinad, Kobe, Hyogo 658, Japan

Abstract

The synthetic route developed on the despyrrole analogs of clavines was successfully applied to the first total synthesis of (±)-fumigaclavine B (1) and (±)-isolysergine (2), thus firmly established the structure of the former alkaloid (1).

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1929-1932
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DOI: 10.3987/R-1985-08-1929
Synthesis of New Penem Derivatives: N-Substituted Analogs of FCE 22101

Carlo Battistini,* Sergio Vioglio, Cosimo Scarafile, and Giovanni Franceschi

*Ricerca&Sviluppo Chimico, Farmitalia Carlo Erba SpA, Via dei Gracchi 35, 20146 Milano, Italy

Abstract

New penem derivatives, analogs of FCE 22101 with N-substitution at the cambamoyl moiety, have been synthesized by using a new catalytic action of 4-dimethylaminopyridine.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1933-1942
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DOI: 10.3987/R-1985-08-1933
On the Catalytic Reduction of Some 12-Spiro-derivatives of 8-Aza-11-oxasteroids

Cosimo Altomare, Francesco Campabna, Angelo Carotti,* and Wayne E. Steinmetz

*Dipartimento Farmaco-Chimico, Università di Bari, Via Amendola 173, 70126 Bari, Italy

Abstract

The catalytic reduction over Pd on carbon of some 8-aza-11-oxo-gona- and D-homo-gona-1,3,5(10),6,13-pentaene derivatives 1, carrying either a barbituric or a 1,3-indandione moiety as the spira-substituent at C-12, is reported. Different spectral means, including proton-proton nuclear Overhauser effect (nOe) measurements, have been used to get structure elucidation. A detailed analysis of the 1H-NMR spectra at 400 MHz of some reduction products is also reported.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1943-1946
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DOI: 10.3987/R-1985-08-1943
Photo-induced Formation of meta-Bridged Aromatic Lactams Having Eleven Membered Ring

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

Irradiation of N-[2-(2- or 4-hydroxyphenyl)ethyl]-3-(2-bromophenyl)propionamides (10) under basic conditions gave eleven membered ring lactams (12a,b,e and 13), which were formed by aryl-aryl coupling at the ortho and para positions to a hydroxyl group in 10, in moderate yields.

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Communication | Regular issue | Vol 23, No. 8, 1985, pp.1947-1950
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DOI: 10.3987/R-1985-08-1947
Cyclization of Dinitriles by Hydrogen Halides. 1. Hydrogen Bromide. The Temperatures as a Novel Determining Factor of the Direction of Cyclization

Pedro Victory* and Miquel Garriga

*Departmento de Química Orgánicam Instituto Químico de Sarriá, Universitat de Barcelona, 08028 Barcelona, Spain

Abstract

A selective synthesis of the 2-amino-4-bromo- and 4-amino-2-bromo-5,6-dihydro-5-methylpyrido[2,3-d]pyrimidin-7(8H)-ones (2 and 3) by temperature control in the cyclization reaction of the 6-cyanamino-5-cyano-3,4-dihydro-4-methyl-2-pyridone (1) with hydrogen bromide is described. The structure of the isomer obtained in each case is assigned unequivocally.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.1951-1954
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DOI: 10.3987/R-1985-08-1951
The Isolation and Structure of Buxaqumarine — A New Steroidal Alkaloid from Buxus papilosa

Atta-ur-Rahman,* M. Iqbal Choudhary, and Mehrun Nisa

*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan

Abstract

A new steroidal alkaloid, buxaquamarine, has been isolated from the leaves of Buxus papilosa to which structure (I) has been assigned.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.1955-1960
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DOI: 10.3987/R-1985-08-1955
Unsymmetrically Substituted Furoxans. 10. Acetyl-methyl-furoxans

Rosella Calvino, Bruno Ferrarotti, Anna Serefino, and Alberto Gasco*

*Istituto di Chimica Farmaceutica e Tossicologica, Università di Torino, Corso Raffaello 31, 10125 Torino, Italy

Abstract

The two isomeric acetyl-methyl-furoxans have been prepared. Discussion of their structures and thermal equilibration and kinetics of thermal conversion from 3-methyl to 4-methyl isomer are also reported.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.1961-1967
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DOI: 10.3987/R-1985-08-1961
Aminopyrimidines and Derivatives. XVIII. Reactions of 1,6-Dihydro-4-β-D-(2’,3’,4’,6’-tetra-O-acetyl)glucopyranosylamino-2-methylthio-6-oxopyrimidine with Electrophiles

A. Sánchez Rodrigo,* M. Nogueras Montiel, J. Colmenero de la Casa, R. Asenjo Asenjo, and M. Melgarejo Sampedro

*Depto. Química Orgánica, Colegio Universitario, 23071 Jaén, Spain

Abstract

Reactions of 1,6-dihydro-4-β-D-(2’,3’,4’,6’-tetra-O-acetyl)glucopyranosylamino-2-methylthio-6-oxopyrimidine with electrophiles may take place on four positions: N1-H, N3-H, C6-OH and/or C5-H. Acidic media induce electrophilic substitution on C5 and basic media on C6-OH. Neither N1 nor N3 are substituted under the above mentioned conditions.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.1969-1981
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DOI: 10.3987/R-1985-08-1969
Fluoroheterocycles II. Synthesis of 3-Fluro-1,2,4-triazine 2-Oxides

Misa V. Jovanovic

*Department of Chemistry, Southern Methodist University, P.O. Box 750314, Dallas, TX 75275-0314, U.S.A.

Abstract

Selected 3-fluoro-1,2,4-triazine 2-oxides were prepared by nitrosation of respective amino compounds and thermolysis of the corresponding diazonium tetrafluoroborate salts. In one instance, the intermediate diazonium salt was isolated; the first stable heterocyclic diazonium salt ever reported.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.1983-1989
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DOI: 10.3987/R-1985-08-1983
Application of the Photo-Fries Rearrangement of Aryl Dihydrocinnamates to the Synthesis of Flavonoids

Hermenegildo García, Sara Iborra, Miguel A. Miranda,* and Jaime Primo

*ETSII, Departmento de Química, Universidad Politécnica de Valencia, Apartado 22012, E-46071 Valencia, Spain

Abstract

The photo-Fries rearrangement of aryl dihydrocinnamates is compared with that of the analogous cinnamates from a preparative point of view. The former proceeds with higher conversions, giving the corresponding 2’-hydroxydihydrochalcones in acceptable yields. This process, combined with well established reactions, provides an alternative entry to the synthesis of flavonoids.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.1991-1997
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DOI: 10.3987/R-1985-08-1991
Total Synthesis of Cleomiscosin B, a Coumarinolignoid

Hitoshi Tanaka, Ichiro Kato, and Kazuo Ito*

*Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tenpaku, Nagoya 468-8503, Japan

Abstract

Direct alkylation of fraxetin (3) with ethyl 2-bromo-3-(4-benzyoxy-3-methoxyphenyl)-3-oxopropionate (4) by utilizing about 1 equivalent of sodium hydride afforded the desired compound (6) as the major product, which was reduced with lithium borohydride in tetrahydrofuran to give the threo and erythro isomers (7a,b). The isomers underwent cyclization reaction with 5% sulfuric acid and subsequent hydrolysis of the cyclization product (10) furnished cleomiscosin B (1).

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Report | Regular issue | Vol 23, No. 8, 1985, pp.1999-2003
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DOI: 10.3987/R-1985-08-1999
Activated Nitriles in Heterocyclic Synthesis: Novel Synthesis of Pyridazines, Pyridines, Pyrazoles and Polyfunctionally Substituted Benzene Derivatives

Galal Eldin Hamza Elgemeie,* Hassan Attia Elfahham, Sherif Elgamal, and Mohamed Hilmy Elnagdi

*Chemistry Department, Faculty of Science, Minia University, Minia, Egypt

Abstract

Knoevenagel condensation of benzoylacetonitrile with malononitrile afforded the corresponding ylidene derivative which could be converted into pyridazine derivative on coupling with benzenediazonium chloride and cyclization. Similarly benzoylacetonitrile underwent self condensation to yield either the benzene derivative or the ylidene derivative. The latter could be converted into a variety of heterocyclic derivatives on reaction with malononitrile, ethyl cyanoacetate, hydrazine hydrate and benzenediazonium chloride.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.2005-2012
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DOI: 10.3987/R-1985-08-2005
Synthesis of the Enantiomers of Erythro-2-oxiranyl-1,4-benzodioxan

Robin D. Clark* and Lilia J. Kurz

*Institute of Organic Chemistry, Syntex Research, Palo Alto, California 94304, U.S.A.

Abstract

(2R, 1’S) and (2S, l’R)-2-Oxiranyl-1-4-benzodioxan (2R, 1’S-1and 2S, 1’S-1) were prepared in six steps from 2-benzyloxyphenol. The key step in each synthesis was the enantioselective Sharpless epoxidation of allylic alcohol 4.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.2013-2017
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DOI: 10.3987/R-1985-08-2013
On the Reanction of Cyanoacetohydrazine with α-Substituted Cinnamonitriles

Nazario Martín, Carlos Seoane, and José L. Soto*

*Departamento de Química Orgánica, Facultad de Química, Universidad Complutense de Madridas, Ciudad Universitaria, E-28040 Madrid, Spain

Abstract

The condensation of cyanoacetohydrazide with benzylidenemalononitriles is reinvestigated and a structure of 1,6-diamino-3,5-dicyano-2-pyridone is confirmed on the basis of chemical and spectroscopic evidence.

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Report | Regular issue | Vol 23, No. 8, 1985, pp.2019-2023
Published online:
DOI: 10.3987/R-1985-08-2019
[4+2] Cycloadditions of 3-Methyl-5-vinylisoxazole

Alberto Brandi,* Francesco De Sarlo, Antonio Guarna, and Andrea Goti

*CNR, Centro di Studio Sulla Chimica e la Struttura dei Composti Eterociclici e lolo Applicazioni, c/o Dipartimento di Chimica Organica "Ugo Schiff", Università di Firenze, Via Gino Capponi 9, I-50121 Firenze, Italy

Abstract

3-Methyl-5-vinylisoxazole is reported to undergo Diels-Alder cycloadditions with activated dienophiles

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Report | Regular issue | Vol 23, No. 8, 1985, pp.2025-2034
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DOI: 10.3987/R-1985-08-2025
A Facile Synthesis of Novel Tricyclic Compounds, Tetrazoloquinoxalines and 1,2,4-Triazoloquinoxalines

Kenji Makino,* Gozyo Sakata, Katsushi Morimoto, and Yoshinori Ochiai

*Central Research Institute, Nissan Chemical Industries Ltd., 722-1 Tsuboicho, Funabashi, Chiba 274-8507, Japan

Abstract

Novel 5-methyltetrazolo[1,5-a]quinoxalin-4-ones (5) and 5-methyl-1,2,4-triazolo[4,3-a]quinoxalin-4-ones (7) could be synthesized from 1-methyl-3-chloroquinoxalin-2-ones (3) and 1-methyl-3-hydrazinoquinoxalin-2-ones (6), respectively. Further extensive study was carried out to synthesize 4- or 7-substituted and 4,7-disubstituted tetrazolo[1,5-a]quinoxalines (10) and 1,2,4-triazolo[4,3-a]quinoxalines (12).

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Report | Regular issue | Vol 23, No. 8, 1985, pp.2035-2039
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DOI: 10.3987/R-1985-08-2035
Lead(IV) Acetate-Metal Halide Reagents III. A New Method for the Synthesis of Tetrahydrofuran, Tetrahydropyran and Lactone Derivatives

Shigayasu Motohashi,* Masakichi Satomi, Yasuo Fujimoto, and Takashi Tatsuno

*College of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan

Abstract

A new method for the synthesis of tetrahydrofuran, tetrahydropyran and lactone derivatives from γδ-, γε-unsaturated alcohols and βγ-, γδ-carboxylic acids is described.

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38 data found. 1 - 30 listed Next Last