HETEROCYCLES

■ A Novel Synthesis of Aporphine and Dehydroaporphine C7-C7’ Dimers

L. Castedo,* R. Riguera, J. M. Sáa, and R. Suau

*Departamento de Química Orgánica , Facultad de Farmacia, Universidad de Santiago de Compostela, E-15706, Santiago de Compostela, Spain

Abstract

Dehydroglaucine (4) and dehydronuciferine (5) easily undergo C7-C7’ coupling by reaction with mercuric salts to give the corresponding aporphine and dehydroaporphine dimers. The reaction appears to be solvent dependant.

■ Reactions of 3-Diazopyrazolo[3,4-b]pyridine with Some Reactive Methylene Compounds and Cycloadditions

Marjan Kocevar, Branko Stanovnik, and Miha Tisler*

*Department of Chemistry, University of Ljubljana, 61000 Ljubljana, Yugoslavia

Abstract

3-Diazopyrazolo[3,4-b]pyridine is transformed with reactive methylene compounds into polycyclic 1,2,4-triazine derivatives via the coupling products. A cycloaddition reaction and reaction with 2,5-dimethylfuran are also described.

■ A New and Facile Synthesis of Oxazolo[5,4-d]pyrimidine Derivatives

Keitaro Senga,* Junko Sato, and Sadao Nishigaki

*Pharmaceutical Institute, School of Medicine, Keio University, Shinanomachi 35, Shinjuku, Tokyo 160-0016, Japan

Abstract

Treatment of 5-benzylideneamino-1,3-dimethylbarbituric acids with thionyl chloride afforded the corresponding oxazolo[5,4-d]pyrimidines in high yields.

■ Nitrosative Cyclization of 1,3-Dimethyl-6-(α-methylbenzylidenehydrazino)uracils to 6-Aryl-1,3-dimethyllumazines

Keitaro Senga,* Yukako Kanamori, and Sadao Nishigaki

*Pharmaceutical Institute, School of Medicine, Keio University, Shinanomachi 35, Shinjuku, Tokyo 160-0016, Japan

Abstract

The reaction of 1,3-dimethyl-6-(α-methylbenzylidenehydrazino)uracils with sodium nitrite in acetic acid, followed by treatment with sodium dithionite in formic acid furnished the corresponding 6-aryl-1,3-dimethyllumazines.

■ Photochemical Cyclization of Epoxy-alcohol. A New Synthesis of Sugiresinol Dimethyl Ether

Zen-ichi Horii, Chuzo Iwata,* Tetsuaki Tanaka, and Takefumi Momose

*Faculty of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Toyonaka, Osaka 560-0043, Japan

Abstract

Photochemical cyclization of 1,3-bis(4-methoxyphenyl)-4,5-epoxy-1-pentanol gave sugiresinol dimethyl ether in good yield.

■ Studies on the Furan Series. Part VIII. The Reaction of Ynamines with Acyloins. A Convenient Preparation of 4,5-Di(2-furyl and 2-thienyl)-2-(5H)-furanones and -furans

Seppo I. Pennanen*

*Laboratory of Organic Chemistry, Helsinki University of Technology, P.O. Box 6100,FIN-02015 HUT, Espoo, Finland

Abstract

In the reaction of 1-diethylaminopropyne with heteroaromatic acyloins three different competing reactions take place: cycloaddition, protonation and oxidation (followed by cycloaddition)giving the 2(5H)-furanone V, the 2-aminofuran VI and the α-diketone III (the amide IV), respectively. When heteroaromatic α-diketones (III) are used as starting material, 4,5-di(2-furyl and 2-thienyl)-2(5H)-furanones (V) and -furans (VIII) are readily prepared in good yields.

■ The Synthesis of (±)-Peshawarine, (±)-Aobamine and (±)-Corydalisol, and the Absolute Configurations of (-)-Peshawarine and (+)-Canadaline

Maurice Shamma,* Alan S. Rothenberg, and S. Fazal Hussain

*Department of Chemistry, The Pennsylvania State University, York Campus, P1031 Edgecomb Avenue, York, Pennsylvania 17403, U.S.A.

Abstract

The first total syntheses of racemic peshawarine (1), aobamine (4) and corydalisol (5) have been achieved starting from synthetic coptisine (6). (-)-Peshawarine (1) has been interrelated with (+)-rhoeagenine methiodide (14) of known chirality. The absolute configuration of (+)-canadaline (16) has also been established through correlation with (+)-stylopine (18) of known stereochemistry.

■ Conversion of Rhoeadine Methiodide into the Alkaloid Peshawarine

Vilím Simánek, Vladimír Preininger, Frantisek Santavy,* and Ladislav Dolejs

*Department of Organic Chemistry, Palacky University, Trida Svobody 8 ,77146 Olomouc, Czech Republic

Abstract

The Emde degradation of rhoeadine methiodide (4. MeI) afforded the acetal 5 from which racemic peshawarine (1) was prepared.

■ Reaction of Lithio Diethylsuccinate with Carbonyl Compounds: Stobbe Condensation of α-Ketoesters

Vichai Reurrakul,* Kosan Kusamran, and Sompong Wattanasin

*Department of Chemistry, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand

Abstract

The Stobbe condensation of α-ketoesters was successfully carried out by a two-step procedure. The reaction of lithio diethylsuccinate with α-ketoesters gave the corresponding γ-butyrolactones. Treatment of the lactones with potassium t-butoxide in t-butanol yielded the expected Stobbe products.

■ Synthesis of Ethyl 1-Phenyl- and 2-Methyl-6H-furo[2,3-d][1]benzazepine-5-carboxylates

Kenichi Yakushijin, Shigetaka Yoshina,* and Akira Tanaka

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

Abstract

Thermolysis of ethyl α-azido-β-(3-phenylfuryl-2)acrylates (1a,b) in ligroin gave ethyl 1-phenyl- or 2-methyl-4H-furo[2,3-d][1]benzazepine-5-carboxylates (2a,b). Further thermolysis of 2a and 2b in boiling xylene yielded ethyl 1-phenyl- and 2-methyl-6H-furo[2,3-d][1]benzazepine-5-carboxylates (3a,b), respectively.

■ The Synthesis of Thieno[3,2-e]pyrazolo[4,3-c]pyridine. A New Heterocyclic System

Misbahul Ain Khan* and Antonio Elydio Guarçobi

*Seção de Quimica, Instituto Militar de Engenharia, Urca, 20.000 Rio de Janeiro, RJ, Brazil

Abstract

The synthesis of the title heterocyclic system from appropriate thieno[2,3-b]pyridine is reported.

■ The Application of Heterocycles to the Synthesis of Carbonyl Compounds

John ApSimon* and Andrew Holmes

*Department of Chemistry, Carlton University, 1125 Colonel By Drive, Ottawa Ont. KaS 5B6, Canada

Abstract

The role of heterocyclic compounds in the synthesis of substituted aldehydes and ketones is reviewed. Particular note is made of the charge polarization of the masked carbonyl function and the sites of alkylation available with each heterocycle are considered. A total of eleven heterocycles are discussed.

■ The Reaction of 3,5-Dimethylisoxazole with Some Electrophiles

Choji Kashima,* Yasuhiro Yamamoto, and Yoshihiko Tsuda

*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan