Regular Issue

Vol. 27, No. 1, 1988

42 data found. 1 - 30 listed Next Last
Communication | Regular issue | Vol 27, No. 1, 1988, pp.1-5
Published online:
DOI: 10.3987/COM-87-4259
Diterpenoid Alkaloids from Delphinium peregrinum. The Structure of Peregrine

Gabriel de la Fuente,* José A. Gavín, Rafael Díaz Acosta, and José A. Morales

*Instituto de QUímica Orgánica, Instituto de Productos Naturales Orgánicos, Instituto de Productos Naturales Orgánicos, La Laguna, Tenerife, Canary Islands, Spain

Abstract

From Delphinium peregrinum var. elongatum Boiss.,bicoloridine, dihydrogadesine, nudicaulidine, 13-acetylhetisinone, and a new C-19 diterpenoid alkaloid peregrine were isolated. The structure of the new base was determined from chemical and spectral evidence.

PDF (108KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.7-10
Published online:
DOI: 10.3987/COM-87-4285
Cyclosdditions with Acylhydrazones. Selective Diastereomeric Pyrazolidine Synthesis and Nitrile Acylimine Synthons

Mohamed A. Badawy, Said A. El-Bahaie, Azza M. Kadry, and Yehia A. Ibrahim*

*Department of Chemistry, Faculty of Science, University of Cairo, Giza, Egypt

Abstract

Arylaldehydes N-acylhydrazones 1 undergo dipolar cycloadditions to N-arylmaleimides 2 to give two diasteromeric kinetic and thermodynamic pyrazolidines 3 and 4. Oxidation of 3 and 4 gave the corresponding pyrazolines 5 which were also obtained directly from compounds 1 and 2 in nitrobenzene. The present investigation offers an easy access to nitfile acylimine synthons 6.

PDF (100KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.11-12
Published online:
DOI: 10.3987/COM-87-4295
Sodium Borohydride Desulphurization of Thiolactams to Amines

Sukhendu B. Mandal, Venkatachalm S. Glrl, and Satyesh C. Pakrashi*

*Indian Institute of Chemical Biology, Calcutta-700 032, India

Abstract

Sodium borohydride desulphurizes a variety of thiolactams(1-8) in t-butanol/methanol mixture under reflux to the respective amines (9-16) in good yield.

PDF (46KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.13-16
Published online:
DOI: 10.3987/COM-87-4311
Direct Thiation of 7-Theophyline Nucleosides

Rodrigo Rico-Gómez,* Manuel L. Ruiz-Mora, Ezequiel P. de Inestrosa Villatoro, and Josefa Rios-Ruiz

*Deparament de Bioquimica, Biologai Molecular y Quimica Orgánica, Universidad de Málaga, 29071 Málaga, Spain

Abstract

8-Methyl-6-thiotheophylline nucleosides have been obtained by treatment of the corresponding 8-methyl-theophylline nucleosides with Lawesson’s Reagent.

PDF (87KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.17-20
Published online:
DOI: 10.3987/COM-87-4312
High Regio- and Stereoselective Cycloaddition of a Nitrone to Alkylidenecyclopropanes

Alberto Brandi,* Silvio Carli, 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

The 1,3-dipolar cycloaddition of 5,5-dimethylpyrroline-N-oxide (DMPO) 3 to methylenecyclopropanes substituted on the exocyclic double bond gives exclusively 4-spirocyclopropane isoxazolines when the substituent is aryl or alkyl group, 5-spirocyclopropane iaoxazolines when the substituent is an electron-withdrawing group. This cyclic nitrone gives cycloadducts with high diastereoselectivity.

PDF (104KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.21-26
Published online:
DOI: 10.3987/COM-87-4314
Highly Stereoselective Cyclization of Epoxyketone Promoted by Acid

Toshio Suzuki,* Etsuko Sato, Hitomi Ihara, Katsuo Unno, and Tetsuji Kametani*

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

Abstract

Epoxidation of the protected ally1 alcohol (8) with m-chloroperbenzoic acid provided the unexpected 1-oxa-bicyclo[3.2.03,6]heptane (11) along with the corresponding epoxyketone (10) which was easily converted to (11) by acid.

PDF (71KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.25-29
Published online:
DOI: 10.3987/COM-87-4333
A Novel Triflate Mediated Approach to Alkaloidal Glycosides

Zaheer Ahmad, Najam-ul-Hussain Kazmi, Abdul Qasim Khan, and Abdul Malik*

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

Abstract

A mild one pot synthesis of alkaloidal glycosides is reported. In the reaction sequence, classical SN2 displacement of the trifluoromethanesulfonyloxy group in sugar triflate (1) was affected with nucleophilic nitrogen of a variety of naturally occurring alkaloidal bases (2-10) affording alkaloidal N-glycoeides (11-9). Deprotection of the sugar moiety in (11)(18) end (19) with boron trichloride afforded the deprotected compounds (20-22). The strategy provides s general method for the preparation of pharmacologically interesting compounds from readily accessible precursors.

PDF (108KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.31-34
Published online:
DOI: 10.3987/COM-87-4324
Chemistry of the 5:7-Fused Heteroaromatic Systems: A Novel Rearrangement Involving the Imidao[4,5-e][1,3,4]triazepine and Pyrazolo[3,4-e][1,3,4]triazapine Systems

Ramachandra S. Hosmane* and Benjamin B. Lim

*Labratorl for Chamical Dynamics, Department of Chemistry, University of Maryland Baltimore County, Catonsville, Maryland 21228, U.S.A.

Abstract

A novel rearrangement which involves the potential intermediacy of an imidazo[4,5-e]- or a pyrazolo[3,4-e][1,3,4]triazepine is reported.

PDF (94KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.35-38
Published online:
DOI: 10.3987/COM-87-4326
Two New Oxazoles from Amyris texana P. Wilson

Xorge A. Domínguez, Gabriel de la Fuente,* Antonio G. González, Matís Reina, and Isabel Timón

*Instituto de QUímica Orgánica, Instituto de Productos Naturales Orgánicos, C. S. I. C./ Unversidad de La Laguna, La Laguna, Tenerife, Canary Islands, Spain

Abstract

From the roots of Amyris texana P. Wilson, two new oxazoles, texamine (1) and texaline (2) were isolated together with 0-isopentenylhalfordinol (3). The structures of the new compounds were established by spectroscopic methods, including long-range HETCOR 2-D nmr.

PDF (83KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.39-44
Published online:
DOI: 10.3987/COM-87-4329
Procumbine, a New Secoberbine Alkaloid

Eva Táborksá, Frantisek Vezník, Jirí Slavik, Petr Sedmera, and Vilím Simánek

*Institute of Medical Chemistry, Palacky University, 3, Hnevotínská, 775 15 Olomouc, Czech Republic

Abstract

The structure determination of the secoberbine alkaloid procumbine (2) isolated from Hypecoum procumbens and H. leptocarpum is reported.

PDF (92KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.45-48
Published online:
DOI: 10.3987/COM-87-4337
Synthetic Approach to the Ivermectin Bottom Half Using Internal Cycloadducts of N-Furfuryl Acrylamides: Functionality and Optical Activity

Michael E. Jung* and Leslie J. Street

*Department of Chamistry and Biochemistry, University of California Los Angeles, Los Angels CA 90024, U.S.A.

Abstract

The 2-(α-benzyloxyacetyl) furan 2b is converted into the aminal 3b which undergoes intemal cycloaddition to give a highly oxidized intermediate 5b in a potential route to ivermectin 1, while the use of (S)-valinol in this sequence permits the ready preparation-separation of both enantiomers of 5a.

PDF (93KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.49-55
Published online:
DOI: 10.3987/COM-87-4346
2-(Heteroatom-substituted)methyl Penems. II. Sulphinyl and Sulphonyl Derivatives

Marco Alpegiani, Ettore Perrone, and Giovanni Franceschi

*Farmitalia Carlo Erba R&D, Via dei Gracchi 35, 20146 Milano, Italy

Abstract

Thermodynamic control of the endo-exo double bond equilibration in 2-(thiosubstituted) methyl penems allowed the synthesis of the sulphinyl and sulphonyl derivatives, which proved to be potent antibacter~al agents.

PDF (173KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.57-61
Published online:
DOI: 10.3987/COM-87-4348
A New Intermediated for Methyl Jasmonate and PG‘s from Iridoid Glucoside Aucubin

Enrico Davini, Carlo Iavarone, and Corrado Trogolo

*Centro CNR per lo Studio della Chimica delle Sostanze Organiche Naturali, Dipartmento di Chimica, Università degli Studi di Roma "La Sapienza", Piazzale Aldo Moro 5, 00185 Roma, Italy

Abstract

A synthetic approach to biologically active cyclopentanoids or their intermediates starting from natural heterocyclic precursors (iridoid glucosides) has been devised. Aucubin 1 was efficiently converted into chiral cyclopentenone 9 ,intermediate for synthesis of methyl jasmonate-type compounds and prostaglandins.

PDF (130KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.63-66
Published online:
DOI: 10.3987/COM-87-4352
Ptactical Synthesis of Nojirimycin

Yoshisuke Tsuda,* Yukihiro Okuno, and Kimihiro Kanemitsu

*Faculty of Pharmaceutical Scicences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan

Abstract

The short step and efficient synthesis of nojirimycin (1) from commercially available 1,2-isopropylidene-D-glucofuranose (2) was described. Oxidation of 2 with (Bu3Sn)2O-Br2 followed by oximation, isomerization, and stereoselective reduction gave the 5-amino derivative of glucoconfiguration (6a), which was converted to nojirimycin bisulfite adduct (8) in 50% overall isolated yield.

PDF (98KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.67-70
Published online:
DOI: 10.3987/COM-87-4362
Novel Aldol-type Reaction Utilizing 3-Methyl-2-phenyl-2-(2-oxoalkyl)benzothiazoline as an Enolate Transferring Reagent

Hidenori Chikashita,* Shi-ichiro Tame, and Kazuyoshi Itoh

*Department of Applied Chemistry, Faculty of Engineering, Kansai University, Suita, Osaka 564-8680, Japan

Abstract

An enolate transfer-type aldol reaction of the title benzothiazoline with aldehydes was successfully achieved in the presence of SnCl4 to afford the cross aldol products.

PDF (81KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.71-74
Published online:
DOI: 10.3987/COM-87-4364
Facile Synthesis of Alcyclic Nucleosides Using a New Coupling Agent of Zinc Iodide

Yong Hae Kim* and Joong Young Kim

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

Abstract

((1,3-Bis(benzyloxy)-2-propoxy)methyl)-2-thiopyrimidine-, uracil-, 2-thiouracil-, and 2-thioadenine- acyclic nucleosides and (2-acetoxyethoxy methyl)-2-thioadenine-, 2-thiopyrimidine-, uracil-, and 2 -thiouracil-acyclic nucleosides have been successfully synthesized in good yields by N-alkylation using a new Lewis acid, zinc iodide in dimethylformamide.

PDF (101KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.75-81
Published online:
DOI: 10.3987/COM-87-4365
Absolute Configuration of Kuwanon L, a Natural Diels-Alder Type Adduct from the Morus Root Bark

Yoshio Hano, Shinkichi Suzuko, Hideaki Kohno, and Taro Nomura*

*Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan

Abstract

The absolute configuration of kuwanon L (1) isolated from the Morus root bark (Morus alba L., Moraceae) was determined as 2S, 3”R, 4”R, 5”S by circular dichroism (CD) spectroscopic study.

PDF (170KB)
Communication | Regular issue | Vol 27, No. 1, 1988, pp.83-87
Published online:
DOI: 10.3987/COM-87-4372
Isolation and Structure of New Pseudoguaianolides, 4-Epipulchellin and 4-Epineopulchellin from Gaillardia Pulchella

Kenzo Hariyama, Hitoshi Hori, Tamiko Ohkura, Takeshi Kawamata, Ji-Fu Gao, and Seiichi Inayama*

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

Abstract

The structure of 4-epipulchellin (1a) and 4-epineopulchellin (1b), new pseudoguaianolide sesquiterpene lactones isolated from Gaillardia pulchella, was determined on the basis of spectroscopic data and chemical transformations from pulchellin (2a) and neopulchellin (2b) into 1a and 1b, respectively.

PDF (147KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.89-92
Published online:
DOI: 10.3987/COM-87-4194
Papillamidine - A New Steroidal Alkaloid from the Leaves of Buxus papillosa

Atta-ur-Rahman,* Muzaffar Alam, Gulzar Ahmed, and Muhammad Iqbal Choudhary

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

Abstract

A new steroidal alkaloid, papillamidine, has been isolated from the leaves of Buxus papillosa, to which structure 1 has been assigned.

PDF (76KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.93-100
Published online:
DOI: 10.3987/COM-87-4240
Synthesisabd Characerization of Isomeric 2,3,3a,4-Tetrahydro-1H-pyrrolo[1,2-a]benzimidazol-1-ones from 1,2-Phenylenediamines and 3-Acylpropionic Acids

Alba Chimirri, Silvana Grasso, Pietro Monforte, Giobanni Romeo, and Maria Zappalà

*Dipartimento Farmaco-Chimico, Università di Messina, Viale Annunziata, 98168 Messina, Italy

Abstract

Synthesis and identification of isomeric 2,3,3a,4-tetrahydro-1H-pyrrolo[1,2-a]benzimidarol-1-ones are described. A mechanism for their formation is suggested by evaluating the effects of substituents on the phenylenediamine ring in the reaction of 1,2-phenylenediamines and-3-acylpropionic acid. The structures of obtained adducts have bean assigned by means of 1H nmr spectra assisted by NOE measurements.

PDF (181KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.101-103
Published online:
DOI: 10.3987/COM-87-4247
Daturilinol - A New Withanolide from the Leaves of Datura metal

Tariq Mahmood, S. Salman Ahmad, and Salimuzzaman Siddiqui

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

Abstract

A withanolide daturilinal (1) has been isolated from the fresh leaves of Datura metel and its structure elucidated through spectral studies.

PDF (85KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.105-112
Published online:
DOI: 10.3987/COM-87-4261
Studies on the Synthesis of Heterocyclic Compounds. Part XII. Pyrazolo[4,3-c]-1,5-banzodiazocine-4,10-dione. A New Ring System

Salvatore Plescia,* Maria Luisa Bajardi, Giuseppe Daidone, and Angela Roccaro

*Dipartimento di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo , Via Archirafi n 32 90123 Palermo, Italy

Abstract

Treatment of N-(1-R-4-carboxypyrazol-5-yl)-2-aminobenzamides 2b,e with thionyl chloride afforded new pyrazolo[3,4-d]-1,3-oxazinones 3b,e. When the amide group of compounds 2b,e was blocked pyrazolo[4,3-c]-1,5-benzodiazocine-4,10-diones 6a,d were obtained.

PDF (226KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.113-124
Published online:
DOI: 10.3987/COM-87-4267
Photochemistry of Pyridine N-Oxides. Trapping of an Intermediate with Amines

Angelo Albini, Elisa Fasani, and Christian Lohse

*Department o f Organic Chemistry, University of Pavia, Via Taramelli 10, 27100 Pavia, Italy

Abstract

The photochemistry of pyridine N-oxide (1a) and the corresponding 4-benzyl (1b),4-phenyl (1c), and 2,6-dimethyl (1d) derivatives has been investigated or reinvestigated. Substrates 1a and 1b yield a small amount of the corresponding 2-acylpyrroles (5a,b) as the only isolable product. 1d yields 5d in moderate yield and 1c yield 5c in aprotic and the 2-pyridone 7c in protic solvents. In the presence o f diethylamine isomeric 5-diethylaminopentadienenitriles (3,4) are obtained in moderate yield along with deoxygenated pyridines (6). Under this condition no 5 is formed, but the yield of 7 is unchanged. These reactions are most economically accounted for by admitting that nitrene 11 is formed as an intermediate and undergoes rearrangement to pyrroles 5 or polymerization to tars, or it can be trapped by amines (proton abstraction followed by nucleophilic substitution) to yield products 3 and 4. The lactams 7 arise directly from the N-oxide singlet excited state, which is also involved in the deoxygenation by amines.

PDF (281KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.125-132
Published online:
DOI: 10.3987/COM-87-4293
Steteoselective Synthesis of Unsaturated Oxetanes

Alexandre Feigenbaum,* Jean-Pierre Pete, and Anne-Lise Poquet-Dhimane

*Laboratoire de Photochimie, U.A. CNRS n°459, UFR Sciences, 51062 Reims, France

Abstract

Butynones 1 and 7 add on alkenes under UV irradiation to afford α-alkynylaretones. The oxetanes obtained with cyclic alkenes have been shown to hove the triple bond endo. Adducts with furan have been converted to an α-vinyloxetane 6 having the double bond endo.

PDF (204KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.133-148
Published online:
DOI: 10.3987/COM-87-4300
Photocyclisation of Keto-lactams. A New Synthesis of Functionalized 1-Azabicyclo(x.y.o)alkanes

Assia Azzouzi, Moniquw Dufour, Jean-Claude Gramain,* and Roland Remuson

*Laboratoire de Chimie et Biochimie des Substances Naturtelles, U.A. C.N.R.S., Université de Clermont II, Université de Clermont II, France

Abstract

A series of 1-azabicyclo(x.y.o)alkanes has been synthesized using an intramolecular photoreduction reaction. The methodolgy consists of a regioselective abstraction of an hydrogen α to the nitrogen of an amide by the triplet T1(n,π*) of a carbonyl derivative.

PDF (454KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.149-153
Published online:
DOI: 10.3987/COM-87-4308
Effect of Metal Ions in Organic Synthesis. XXXVI. One-pot Synthesis of New 3-Carbonyl- and 3-Carbonyl-N-phosphorus-1-aminopyrroles

Orazio A. Attanasi,* Paolino Filippone, Paola Guerra, and Franco Serra-Zanetti

*Istituto di Chimica Organica , Facolta di Scienze, Università di Urbino, Piazza della Repubblica 13, I-61029 Urbino, Italy

Abstract

The one-pot synthesis of a lot of - new 3-carbonyl-N-phasphorus-1-aminopyrroles and 3-carboxy-N-phosphorus-1-aminopyrroles by reaction of some N-phosphinic and N-phusphonic conjugated azoalkenes with β-diketones and β-ketoesters is reported. A different role played in these reactions by copper(II) chloride catalyst was also observed.

PDF (99KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.155-160
Published online:
DOI: 10.3987/COM-87-4313
Reaction of 1,4-Diaza-1,3-butadienes with Cyanotrimethylsilane. Synthesis of 2,3-Bis(arylamino)propenenitriles and Their Cyclization to 1,4-Diaryl-2,3-dioxo-5-pyrazinecarbonitriles

Masahiko Takahashi,* Hiroaki Miyahara, and Noriyuki Yoshida

*Department of Materials Sciences, Faculty of Engineering, Ibaraki University, 4-12-1 Nakanarusawamachi, Hitachi, Ibaraki 316-8511, Japan

Abstract

Reaction of 1,4-diaza-1,3-butadienes (1) with cyanotrimethylsilane gave 2,3-bis(arylamino)propenenitriles (4), which were cyclized to 1,4-diaryl-2,3-dioxo-5-pyrazinecarbonitriles (5) on treatment with oxalyl chloride. The propenenitriles (4) were oxidized by oxygen to 2,3-bis(arylimino)- propanenitriles (7) , which were chlorinated with thionyl chloride to yield 2,3-bis(ary1imino)-3-chloropropropanenitril (9).

PDF (137KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.161-171
Published online:
DOI: 10.3987/COM-87-4320
Carbodiimide-mediated Annelation of a [1,2,4]Triazole Ring into a Heterocyclic Ring: Synthesis of [1,2,4]Triazolo[4,3-b]triazole, Imidazo[1,2-b][1,2,4]triazole and [1,2,4]Triazolo[1,5-d][1,2,4]triazine Derivatives

Pedro Molina,* Mateo Alajarín, Alicia Ferao, Angeles Lorenzo, Ma Jesús Vilaplana, Enrique Aller, and José Planes

*Departmento de Química Orgánica, Facultad de Ciencias, Universidad de Murcia, 30071 Murcia, Spain

Abstract

The N-aminoazoles 1 and 4 react with diarylcarbdiimides to give the corresponding N-guanidinoazoles which undergo base-catalyzed cyclization to give the fused [1,2,4]triazoles 3 and 6 respectively.The reactions of N-aminotriazines 7 and 8 with diarylcarbodzimides lead directly to the new triazolo-trlazines 9 which display mesoionic character.

PDF (262KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.173-183
Published online:
DOI: 10.3987/COM-87-4328
Pseudoesters and Derivatives. XXVIII. The Reaction of 5-Methoxy-3-pyrrolin-2-one and Its 3-Bromo Derivative with Nitrogen and Sulphur Nucleophiles

M. Dolores Jiménez, Raquel Ortega, Amelia Tito, and Francisco Fariña*

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

Abstract

5-Methoxy-3-pyrrolin-2-one (1) reacts with dimethylamine yielding the corresponding conjugate addition product 3a. By using pyrrolidine, piperidine and diethylamine the addition product 3 is accompanied by the 5-dialkylamino-5-pytrolin-2-one 4, which in the latter case is the main component. Similar results are obtained with 3-bromo-5-methoxy-3-pyrrolin-2-one (2) and the afore-mentioned amines. The reaction of 1 and 2 with thiois under basic catalysis gives only the conjugate addition products 7 and 13 respectively.

PDF (307KB)
Paper | Regular issue | Vol 27, No. 1, 1988, pp.185-193
Published online:
DOI: 10.3987/COM-87-4335
Hetisine Derivatives, Part 1: Acetylation and Oxidation of Hetisine

Jan A. Glinski, Balawant S. Joshi, Quing Ping Jiang, and S. William Pelletier*

*Department of Chemistry, Institute for Natural Products Research, The University of Georgia, Chemistry Building, Athens, Georgia 30602-2556, U.S.A.

Abstract

Acetylation of hetisine (1) under drastic conditions afforded 2-acetyl (8), 11-acetyl (9), 13-acetyl (5), 2,11-diacetyl (7), 11,13-diacetyl (2) and 2,11,13-triacetyl (6) hetisines. Sarett oxidation of the compounds (9), (5), (7) and (2) gave 11-acetyl-2,13-didehydro (11), 13-acetyl-2,11-didehydro (12), 13-dehydro-2,11-diacetyl (14) and 2-dehydro-11,13-diacetyl (10) hetisines, respectivsly. Alkaline hydrolysis of (12) and (8) gave 2,11-didehydrohetisine (13) and 2-dehydrohetisine (hetisinone) (3), respectively. Sarett oxidation of hetisine (1) afforded (13) as the major product besides 11-dahylrohetisine (15). All the compounds have been characterized by their ir, ms, 1H nmr and 13H nmr data. The location of keto groups in the hetisine derivatives (3), (10), (11), (12), (13), (14) and (15) has been confirmed by CD and ORD meaeurements.

PDF (247KB)
42 data found. 1 - 30 listed Next Last