HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 9, No. 9, 1978
Published online:
■ Synthesis of 3-Isoquinolines
Hiroshi Fukumi* and Hideshi Kurihara
*Medicinal Chemistry Research Laboratories, Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
Abstract
Treatment of N-benzyl-diethoxyacetamides and N-alkyl-N-benzyl-diethoxyacetamides with sulfuric acid afforded the corresponding 3-isoquinolinols and 2-alkyl-3-isoquinolones, respectively. This reaction is regarded as a kind of Pomeranz-Fritsch synthesis.
Published online:
■ Unusual Formation of Oxazoles by Base- or Acid-catalyzed Ring Opening of 2-Acyl-2H-azirines
Kazuaki Isomura, Youichi Hirose, Hideo Shuyama, Sumiko Abe, Gen-ichiro Ayabe, and Hiroshi Taniguchi*
*Research Institute of Industrial Science, Faculty of Engineering, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan
Abstract
Formation of 2-acyl-2H-azirines was confirmed in thermolyses of β-acylvinyl azides to establish the generality of azirine formation from vinyl azides. Unusual C-C bond fission of 3-unsubstituted 2-acyl-2H-azirine to give oxazole was found to be a base catalyzed reaction. On the other hand, 3-substituted analogues were found to undergo acid-catalyzed reaction to give oxazoles.
Published online:
■ The Reaction of 4-Chloroquinoline 1-Oxide with Activated Acetylenes: Furo[3,2-c]quinolines
Persephone Canonne,* Gilles Lemay, and Rudolph A. Abramovitch
*Département de Chimie, Faculté des Sciences et de Génie, Université Laval, Cité Universitaire, Québec, G1K 7P4, Canada
Abstract
4-Chloroquinoline 1-oxide and ethyl phenylpropiolate in boiling toluene give a mixture of 2- and 3-keto-alkylated products as well as ethyl 2-phenylfuro[3,2-c]quinoline-3-carboxylate. With ethyl acetylenedicarboxylate only low yields of the 2-keto-alkylated product and of the furoquinoline were formed. This is to be contrasted with the observation that 4-chloropyridine 1-oxide and phenylcyanoacetylene or ethyl phenylpropiolate give high yields of the corresponding furopyridine.
Published online:
■ Thiaole N-Oxides from 2-Dialkylamino-1,3-oxathiolium Cation
Kentaro Hirai* and Teruyuki Ishiba
*Shionogi Research Laboratories, Shionogi & Co. Ltd., Fukushima-ku, Osaka 553-0002, Japan
Abstract
Reaction of hydroxylamine with 2-dialkylamino-5-phenyl-1,3-oxathiolium cation gave ω-(dialkylamino-oximinomercapto)acetophenone which was readily cyclized to afford 2-dialkylamino-4-phenylthiazole-3-oxide hydrochloride by ethanolic hydrochloric acid.
Published online:
■ Synthesis of Hypecorine and Hypecorinine Analogs from 3,4-Dihydropapaverine
Vilím Simánek,* Vladimír Preininger, Frantisek Grambel, and Ladislav Dolejs
*Institute of Medical Chemistry, Palacky University, 3, Hnevotínská, 775 15 Olomouc, Czech Republic
Abstract
Reaction of 2’-hydroxymethyl-2-methyl-3,4-dihydropapaverinium (10) and α-oxo-2’-hydroxymethyl-2-methyl- 3,4-dihydropapaverinium salts (11) with hydroxide ions gives cyclic pseudobases 12 and 13, analogs of the alkaloids hypecorine (1) and hypecorinine (2). Derivatives of 2-methylpapaverinium salts form pseudobases by addition of hydroxide ions to immonium bond. Biogenetic conclusions are given.
Published online:
■ Ambiguine and Dihydroajaconine: Two New Diterpenoid Alkaloids from Consolida ambigua
S. William Pelletier,* Rajinder S. Sawhney, and Naresh V. Mody
*Department of Chemistry, Institute for Natural Products Research, The University of Georgia, Chemistry Building, Athens, Georgia 30602-2556, U.S.A.
Abstract
Chemical investigation of the minor alkaloids of Consolida ambigua has led to the isolation and characterization of two new diterpenoid alkoloids, ambiguine (1) and dihydroajaconine (7). Ambiguine is the first lycoctonine-type alkaloid in which a methoxy group is present at the C(8)-position, and dihydroajaconine is a reduced form of the known alkaloid, ajaconine.
Published online:
■ A New Route to (±)-cis-2-Oxabicyclo[3.3.0]oct-6-en-3-one, a Prostaglandin Synthon
Seiichi Takano,* Hiromitsu Iwata, and Kunio Ogasawara
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
A new route to (±)-cis-2-oxabicyclo[3.3.0]oct-6-en-3-one (1), an important prostaglandin synthon, has been developed using a symmetrical starting material (3).
Published online:
■ [2,3]Sigmatropic Rearrangement of N-Substituted Quaternary Salts of Diethyl Pyrrolidinomethylphosphonate
Shinzo Kano,* Satoshi Hibino, and Yasuyuki Tanaka
*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
The base-catalyzed rearrangement of N-benzyl-N-diethylphosphonomethylpyrrolidinium bromide (2) was investigated to afford the diethyl pyrrolidinobenzylphosphonate (3). In a similar fassion, the quarternary salts (4) and (6) were converted to the corresponding substituted diethyl pyrrolidinomethylphosphonates (5) and (7), respectively. Condensation of 3 with anisaldehyde, followed by hydrolysis of the resulting enamine (8) yielded 4-methoxybenzyl 2-methylphenyl ketone (9).
Published online:
■ An Approach to the Skeleton of Rauwolfia Alkaloids. A General Synthesis of 3,8-Epoxy-7-keto-6-oxabicyclo[3.2.1]octane Derivatives
Toshio Suzuki, Akiko Tomino, Seiko Kagaya, Katsuo Unno, and Tetsuji Kametani*
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Hydrolysis of the Diels-Alder adducts (1) and (2), followed by halolactonization, gave 4-bromo- (6) and 4-iodo-3-methoxycarbonyloxymethyl-3,8-epoxy-7-keto-6-oxabicyclo[3.2.1]octane-2-carboxylic acid (8), respectively. Arndt-Eistert reaction of the acid chloride (14), derived from 6, provided the methyl ester (16). The intermediate diazoketone (15) was also transformed to the amides (17) and (18) by condensation with tryptamine and 6-methoxytryptamine, respectively, both of which would be key intermediates for the synthesis of Rauwolfia alkaloids, deserpidine (12) and reserpine (13).
Published online:
■ Oxazoles in Organic Synthesis: Some Observations on the Use of 5-Alkoxyoxazoles in the Diels-Alder Process
Alan P. Kozikowski* and Kimiaki Isobe
*Department of Chemistry, University of Pittsburgh, Parkman Avenue & University Drive, Pittsburgh, PA 15260 , U.S.A.
Abstract
The preparation and Diels-Alder reactivity of 5-ethoxy-2-carboethoxyoxazole and its derivatives have been examined. As a consequence of this investigation, a simple procedure for the preparation of 5-ethoxyoxazole has been discovered.
Published online:
■ Studies on Potential Antitumor Agents (III). Synthesis of 4-Arylcyclophosphamides
Yun-Er Shih, Jy-Shih Wang, and Chao-Tung Chen*
*Institutue of Chemistry, Academia Sinica, 128, Yan-Chiu-Yuan Road, Sec II, Nankang, Taipei,11529, Taiwan, R.O.C.
Abstract
Nine cis-trans pairs of 4-arylcyclophosphamides have been synthesized from benzaldehydes in three steps. Structures were assigned based on infrared spectra.
Published online:
■ Studies in Protoberberibe Alkaloids. XVI. NMR Spectral Studies of 10,11-Dioxygenated 13-Methyltetrahydroprotoberberines
Bantwal R. Pai,* Kuppuswamy Nagarajan, Hosbett Suguna, and Sankaran Natarajan
*Department of Chemistry, Presidency College, Madras 600005, India
Abstract
The NNR chemical shift differences of protons at C13a and C8 and the methyl protons at C13 of cis- and trans-fused 10,11-dioxygenated 13-methyltetrahydroprotoberberines are discussed.
Published online:
■ Kuwanon E, a New Flavanone Derivatives from the Root Bark of the Cultivated Mulberry Tree (Morus alba L.)
Taro Nomura* and Toshio Fukai
*School of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan
Abstract
A new flavanone derivative named kuwanon E was isolated from the root bark of the cultivated mulberry tree (a variety of Morus alba L.). The structure was presumed to be 5,7,2’,4’-tetrahydroxy-5’-geranylflavanone (I) by spectral data.