Regular Issue

Vol. 43, No. 6, 1996

21 data found. 1 - 21 listed
Communication | Regular issue | Vol 43, No. 6, 1996, pp. 1151 - 1158
Published online:
DOI: 10.3987/COM-96-7397
Oxidation of Substituted Pyridines PyrCHRSiMe3 (R=H, Me, Ph) and Substituted Quinolines QnCH2SiMe3 with Hypervalent Iodine Reagents

Ian P. Andrews,* Norman J. Lewis, Alexander McKillop, and Andrew S. Wells

*SmithKline Beecham Pharmaceuticals R &D, Old Powder Mills, nr. Leigh, Tonbridge, Kent, TN11 9AN, U.K.


Oxidation of a variety of substituted pyridines PryCHRSiMe3 (R=H, Me, Ph) and quinolines, QnCH2SiMe3 with hypervalent iodine reagents PIDA, (PhI(OCOCH3)2) and PIFA, (PhI(OCOCF3)2) has been studied. Oxy-desilylation with PIDA/TBAF gives low to moderate yields of PyrCHROR1 and QnCH2OR1 (R1=H,Ac), while good yields of PyrCHROH and QnCH2OH are obtained when PIFA is used.

PDF (142KB)
Communication | Regular issue | Vol 43, No. 6, 1996, pp. 1159 - 1163
Published online:
DOI: 10.3987/COM-96-7430
X-Ray Structures of a Pair of Atropisomers of 1-Acyl-2-arylindolines. Remarkable Through-Space Aryl-Aryl Interaction

Masashi Eto, Fumikazu Ito, Takeo Kitamura, and Kazunobu Harano*

*Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-hon-machi, Kumamoto 862, Japan


A pair of atropisomers due to restricted rotation about Dsp3-Csp2 bond for 1-(4’-nitrobenzoyl)-2-(2"-hydroxynaphthyl)-3,3-dimethylindoline was isolated. The crystal structures of a pairs of the atropisomers indicate the presence of a significant through-space interaction between the aryl moieties.

PDF (136KB)
Communication | Regular issue | Vol 43, No. 6, 1996, pp. 1165 - 1170
Published online:
DOI: 10.3987/COM-96-7434
Intramolecular Cycloadditions with Isobenzofurans - XII - Synthesis and Reactions of Furo[3,4-d]isoxazoles

Stephan Reck, Karsten Bluhm, Tony Debaerdemaeker, Jean-Paul Declercq, Burkhard Klenke, and Willy Friedrichsen*

*Institut für Organische Chemie der Universität, Otto-Hahn-Platz 4, D-24098 Kiel, Germany


The synthesis of furo[3,4-d]isoxazoles (3) and inter- and intramolecular cycloaddition reactions (to 4,5a,b) are reported. The structures of 3k, 5b and 6 have been clarified by X-ray crystallography. Quantum chemical calculations (AM1, PM3, ab initio, density functional methods) concerning the geometry and the different reactivity of benzo[c]furans and furo[3,4-d]isoxazoles were performed.

PDF (219KB)
Communication | Regular issue | Vol 43, No. 6, 1996, pp. 1171 - 1174
Published online:
DOI: 10.3987/COM-96-7437
New Synthetic Route to 3-Furylphosphonates

Chi-Wan Lee and Dong Young Oh*

*Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1, Kusung-Dong, Yusung-Gu, Taejon, 305-701, Korea


A method for the preparation of 3-furylphosphonates has been developed starting with the addition of homoallylic phosphonates to nitrile, followed by a sequence consisting of acidic hydrolysis, iodinemediated cyclization and dehydroiodination by DBU.

PDF (82KB)
Communication | Regular issue | Vol 43, No. 6, 1996, pp. 1175 - 1178
Published online:
DOI: 10.3987/COM-96-7445
A Formal Total Synthesis of Xanthorrhizol Based on Nucleophilic Openig of Vinyloxirane by Arylcopper Reagent

Shinji Nagumo, Shigeyuki Irie, Kazuhito Hayashi, and Hiroyuki Akita*

*School of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274, Japan


A formal total synthesis of xanthorrhizol was achieved in short step sequence involving the nucleophilic opening of methyl 4,5-epoxy-(2E)-pentenoate (1) by arylcopper reagent.

PDF (103KB)
Communication | Regular issue | Vol 43, No. 6, 1996, pp. 1179 - 1184
Published online:
DOI: 10.3987/COM-96-7448
Intramolecular Reissert-Henze Reaction of Isoxazolo[2,3-a]pyridinium Salt; Facile Synthesis of Functionalized Phenacylpyridines from Ethynylpyridines

Nagatoshi Nishiwaki,* Masahiro Ariga, Mitsuo Komatsu, and Yoshiki Ohshiro

*Department of Chemistry, Osaka Kyoiku University, Asahigaoka 4-698-1, Kashiwara, Osaka 582, Japan


Oxidation of 2-(phenylethynyl)pyridine with H2O2-AcOH gave isoxazolo[2,3-a]pyridinium acetate, which was successively attacked by alcohols in the presence of Na2CO3 to afford 6-alkoxy-substituted 2-phenacylpyridines in moderate yields. It was also possible to introduce amino or alkylthio functionality onto the pyridine ring by similar process. The present reaction is a new example of intramolecular Reissert-Henze-type reaction.

PDF (132KB)
Communication | Regular issue | Vol 43, No. 6, 1996, pp. 1185 - 1188
Published online:
DOI: 10.3987/COM-96-7452
Dye-sensitized Photooxidation of 2,4-Disubstituted Imidazoles: The Formation of Isomeric Imidazolinones

Shigeo Kai and Mikio Suzuki*

*Gifu Pharmaceutical University, 6-1, Mitahora-Higashi 5-Chome, Gifu 502, Japan


The photooxidation of 2,4-disubstituted imidazoles (1) in MeOH using hematoporphyrin as a sensitizer afforded isomeric 3-imidazolin-5-ones (2) and 2-imidazolin-4-ones (3).

PDF (103KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1189 - 1199
Published online:
DOI: 10.3987/COM-96-7395
Synthesis of a Carbon-14 Ring-labeled Benzthiophene via Degradation and Recyclization of an Unlabeled Benzthiophene

Scott W. Landvatter

*SmithKline Beecham, Synthetic Chemistry Department, Radiochemistry Section, P.O.Box 1539, UW 2830, King of Prussia, PA 19406, U.S.A.


Synthesis of 7-chloro-2-ethyl-3,4,5,6-tetrahydro-4-methyl-[2-14C]thieno[4,3,2-ef][3]benzazepine (1) has been accomplished via degradation,alkylation and recyclization of an unlabelled benzthiophene. Ozonolysis of the benzthiophene (11a) gave the benzazepinone disulfide (13) which was reduced with tributylphosphine to the thiol (4). Direct treatment of the thiol (4) with ethyl bromo-[2-14C]acetate and sodium ethoxide gave the recyclized benzthiophene (14). The ester side chain of 14 was reduced with LAH to give 14C-labeled form of the original starting material. Transformation to 1 was readily accomplished by a manganese dioxide oxidation, Wittig reaction, catalytic reduction sequence.

PDF (277KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1201 - 1209
Published online:
DOI: 10.3987/COM-96-7416
Synthesis and Basicity of 4-(N,N-Dimethylamino)-2-arylquinazolines

Wojciech Zielinski *, Agnieszka Kudelko, and Elizabeth M. Holt

*Institute of Organic Chemistry and Technology, Silesian Technical University, 44-101 Gliwice, Poland


The reaction of substituted N-phenylbenzimidoyl chlorides with N,N-dimethylcyanamide in the presence of titanium tetrachloride has yielded seven 4-(N,N-dimethylamino)-2-arylquinazolines substituted on the phenyl ring with electron donating or withdrawing groups. pKa values have been determined for these compounds and analyzed in conjunction with the Hammett σ constants to observe the influence of these phenyl substituents upon the basicity of 4-(N,N-dimethylamino)-2-arylquinazolines. The ρ value, single crystal X-ray analysis and 15N-nmr spectra give evidence about the preferential site of protonation in such systems.

PDF (209KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1211 - 1221
Published online:
DOI: 10.3987/COM-96-7417
A Novel Transformation from 5-Aryl-4,4-dimethyl-2-phenylisoxazolidine-3-thiones to 4-Aryl-3,3-dimethyl-2-phenyliminothiethanes

Kwang Soo Yoon, Sung Jae Lee, and Kyongtae Kim *

*Department of Chemistry, Seoul National University, Seoul 151-742, Korea


Treatment of 5-aryl-4,4-dimethyl-2-phenylisoxazolidine-3-thiones with trimethylsilyl iodide (6 molar equiv) in the presence of zinc iodide (2 molar equiv) in chloroform at 50 °C under nitrogen atmosphere gave 4-aryl-3,3-dimethyl-2-(N-phenylimino)thiethanes in good to moderate yields.

PDF (347KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1223 - 1228
Published online:
DOI: 10.3987/COM-96-7428
Total Synthesis of (±)-Gericudranin A

Yoon-Jung Choi, Pil-Jong Shim, Kyung-Soo Ko, And Hee-Doo Kim*

*College of Pharmacy, Sookmyung Women's University, Yongsan-Ku, Seoul 140-742, Korea


An efficient total synthesis of (±)-gericudranin A is described. Trihydroxyacetophenone was converted to (±)-gericudranin A in seven steps via sequential protection, aldol condensation, epoxidation, cationic cyclization, regioselective C-benzylation and deprotection.

PDF (215KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1229 - 1241
Published online:
DOI: 10.3987/COM-96-7440
Preparation of Aza-Analogs of Aplysinopsins and Zwitterionic by Reactions of Heterocumulenes in Naphthyridine's Series

Grégory Delmas, Patricia Deplat, Jean Michel Chezal, Olivier Chavignon,* Alain Gueiffier, Yves Blache, Jean Louis Chabard, Gérard Dauphin, and Jean Claude Teulade

*Département d'Analyse Structurale et de Pharmacologie, Laboratoire de Chimie Organique, Faculté de Pharmacie, 28 Pl. H. Dunant, B.P. 38, 63001 Clermont-Ferrand Cedex 1, France


Imidazo[1,2-a][1,8]naphthyridines (9a,b) having the carbodiimide moiety on the position 1 lead to (Z)-aza-aplysinopsins (10a,b) by solid suported reaction on neutral alumina. By flash chromatography these heterocumulenes are stereosapecifically converted to the corresponding methoxyimidazol-4-ones (11a,b) in good yields. In contrast, tandem aza-Wittig-cyclization reaction of imidazo[1,2-a][1,8]naphthyridine (13) having iminophosphorane moiety on the position 2 gives zwitterionic compounds (14a,b,15) by N-annulation under thermal conditions.

PDF (377KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1243 - 1250
Published online:
DOI: 10.3987/COM-96-7441
Hemsleyanidine and Isohemsleyanidine from Aconitum hemsleyanum var. circinatum

Qing-Yan Xu, Zheng-Ban Li, Feng-Peng Wang, and Chun-Tao Che*

*Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong


Two new norditerpenoid alkaloids, hemsleyanidine (1) and isohemsleyanidine (2), have been isolated from the roots of Aconitum hemsleyanum var. circinatum, along with a known compound talatizamine. The structures of the new compounds were established by chemical and spectroscopic methods (including 1H-, 13C-, and 2-D nmr techniques).

PDF (247KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1251 - 1256
Published online:
DOI: 10.3987/COM-96-7442
New Acridone Derivatives Obtained by Heating the HCl Salt of Acronycine

Shinji Funayama,* Tzu-Yun Pan, Shigeo Nozoe, and Geoffrey A. Cordell

*Department of Bioscience and Biotechnology, Aomori University, Kohbata, Aomori 030, Japan


By heating the HCl salt of acronycine (1), the new acridone derivatives (6,9,13 and 15) were obtained together with noracronycine (2), dihydronoracronycine (3), 1,3-dihydroxy-10-methylacridone (4) linear type dihydro derivative of 2, compound (9) is a furanoacridone derivative with a geminal methyl group and compound (15) is a derivative of 5 with an additional C5 unit.

PDF (180KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1257 - 1266
Published online:
DOI: 10.3987/COM-96-7447
Simple and Efficient One-Pot Preparation of 3-Substituted Coumarins in Water

Gianluca Brufola, Francesco Fringuelli,* Oriana Piermatti, and Ferdinando Pizzo

*Dipartimento di Chimica, Università de Perugia, Via Elce di Sotto, 8 06100 Perugia, Italy


3-Cyanocoumarin and seven derivatives [4-Me; 6-NO2; 7-OH; 7-OMe; 8-OH; 5,7-OMe; 6,7-(-CH=CH-)-2] and eight coumarins substituted at C-3 (CO2Et; NO2; Ph; p-NO2-C6H4; Ph-SO2; 2-pyridyl; 2-thienyl; 2-benzothiazolyl) were prepared, on multigram scale by a one-pot procedure in water alone, by the Knoevenagel reaction of o-hydroxyaryl aldehydes and o-hydroxyacetophenone with acetonitriles. The yields are high and the procedure does not require organic solvents. The reactions carried out in heterogeneous aqueous phase, sometimes in the presence of a surfactant, always have higher yields than the same reactions excuted in homogeneous ethanolic medium.

PDF (233KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1267 - 1270
Published online:
DOI: 10.3987/COM-96-7449
Studies on the Alkaloids from Aconitum karakolicum Rap. Part II

Aina Lao, Yong Wang, Hongcheng Wang, and Yasuo Fujimoto*

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


A novel C19-diterpenoid alkaloid, karaconitine (1) and four known alkaloids, 3-deoxyaconitine (2), aconitine (3), indaconitine (4) and chasmaconitine (5), have been isolated from the roots of Aconitum karakolicum Rap. The structure of karaconitine (1) was determined to be 2α-hydroxy-3-deoxyaconitine by the analyses of its spectral data.

PDF (111KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1271 - 1277
Published online:
DOI: 10.3987/COM-96-7457
New Xenia Diterpenoids from a Soft Coral, Xenia Species

Tetsuo Iwagawa,* Yasuhisa Amano, Hiroaki Okamura, Munehiro Nakatani, and Tsunao Hase

*Department of Chemistry, Faculty of Science, Kagoshima University, Korimoto, Kagoshima 890, Japan


Six new xenia diterpenoids with an opened A-ring containing an aliphatic acid have been isolated from a soft coral Xenia sp. The structures were deterimined on the basis of the spectroscopy.

PDF (230KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1279 - 1286
Published online:
DOI: 10.3987/COM-96-7459
Cyclic Peptides from Higher Plants. Part 30. Three Novel Cyclic Peptides, Yunnanins D, E and F from Stellaria yunnanensis

Hiroshi Morita, Takashi Kayashita, Masako Shimomura, Koichi Takeya, and Hideji Itokawa*

*Department of Pharmacognosy, School of Pharmacy, Tokyo University of Pharmacy & Life Science, Horinouchi 1432-1, Hachioji, Tokyo 192-03, Japan


Three novel cyclic peptides, named yunnanins D [1: cyclo(-Gly-Ile-Ser-Phe-Arg-Phe-Pro-)], E [2: cyclo(-Gly-Ser-δ-Hydroxy Ile-Phe-Phe-Ser-)] and F [3: cyclo(-Gly-Val-Thr-Trp-Tyr-Pro-Ser-Ser-)], have been isolated from Stellaria yunnanensis (Caryophyllaceae) and their structures were elucidated by spectroscopic evidence and chemical degradation.

PDF (232KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1287 - 1300
Published online:
DOI: 10.3987/COM-96-7463
Chiral Synthesis of Furanosesquiterpene, (+)-Ipomeamarone

Keizo Matsuo,* Takahiko Arase, Shigetoshi Ishida, and Yusuke Sakaguchi

*Faculty of Pharmaceutical Sciences, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577, Japan


(+)-Ipomeamarone, a furanosesquiterpene isolated from mold-damaged sweet potato (Ipomea batatas) as one of the phytoalexins, was synthesized starting from (S)-lactic acid as the chiral source using Seebach’s chiral selfreproduction method.

PDF (478KB)
Paper | Regular issue | Vol 43, No. 6, 1996, pp. 1301 - 1304
Published online:
DOI: 10.3987/COM-96-7489
Synthesis and Reactions of 4-Tributylstannyl-3-methylisoxazole

Daishi Uchiyama, Makoto Yabe, Hiroshi Kameyama, Takao Sakamoto,* Yoshinori Kondo, and Hiroshi Yamanaka

*Faculty of Pharmaceutical Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai 980-77, Japan


1,3-Dipolar cycloaddition reaction of bis(tributylstannyl)acetylene with nitrile oxides, followed by treatment with aqueous ammonia in ethanol in a sealed tube gave 4-tributylstannyl-3-methylisoxazole. The palladium catalyzed cross coupling reaction of the isoxazole with 2-iodonitrobenzene, followed by reductive cyclization afforded 3-acetylindole.

PDF (127KB)
Review | Regular issue | Vol 43, No. 6, 1996, pp. 1305 - 1334
Published online:
DOI: 10.3987/REV-95-476
Photochemical Reactions Involving Pyrroles — Part I

Maurizio D'Auria

*Dipartimento di Chimica, Università della Basilicata, Via N. Sauro 85, 85100 Potenza, Italy


The photochemical behaviour of pyrrole derivatives was described showing that the photochemical methodologies in this field can offer some interesting synthetic procedures. Furthermore, pyrrole derivatives has been used in photochemical reactions for the synthesis some interesting products.

PDF (426KB)
21 data found. 1 - 21 listed