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Marquès C, Diaba F, Gómez-Bengoa E, Bonjoch J. Synthesis of the ABC Ring of Calyciphylline A-Type Alkaloids by a Stereocontrolled Aldol Cyclization: Formal Synthesis of (±)-Himalensine A. J Org Chem 2022; 87:10516-10522. [PMID: 35862855 PMCID: PMC9881646 DOI: 10.1021/acs.joc.2c01171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A synthetic approach to a functionalized ABC-tricyclic framework of calyciphilline A-type alkaloids, a building block toward this class of alkaloids, is reported. The key synthetic steps involve a radical cyclization to form the hydroindole system and piperidine ring closure through a stereocontrolled aldol cyclization. The resulting alcohol allows the methyl group to be installed in the bowl-shaped azatricyclic structure; this crucial reaction takes place with configuration retention. The synthesis of azatricyclic compound I constitutes a formal synthesis of himalensine A.
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Affiliation(s)
- Clàudia Marquès
- Laboratori de Química Orgànica, Facultat
de Farmàcia, IBUB, Universitat de Barcelona, Av. Joan
XXIII 27-31, 08028-Barcelona, Spain
| | - Faïza Diaba
- Laboratori de Química Orgànica, Facultat
de Farmàcia, IBUB, Universitat de Barcelona, Av. Joan
XXIII 27-31, 08028-Barcelona, Spain,
| | - Enrique Gómez-Bengoa
- Departamento de Química Orgánica I,
Universidad del País Vasco, Manuel Lardizábal
3, 20018 San Sebastián, Spain
| | - Josep Bonjoch
- Laboratori de Química Orgànica, Facultat
de Farmàcia, IBUB, Universitat de Barcelona, Av. Joan
XXIII 27-31, 08028-Barcelona, Spain,
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Sasaki S, Suzuki H, Ouchi H, Asakawa T, Inai M, Sakai R, Shimamoto K, Hamashima Y, Kan T. Practical synthesis of kainoids: a new chemical probe precursor and a fluorescent probe. Org Lett 2014; 16:564-7. [PMID: 24397779 DOI: 10.1021/ol403434e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A practical total synthesis of kainoid MFPA (5) was achieved in only six steps, via a novel Ni-catalyst-mediated asymmetric conjugate addition reaction. Furthermore, a fluorescein-based fluorescent ionotropic glutamate receptor probe 28 was efficiently synthesized from a precursor derived from a synthetic intermediate of 5.
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Affiliation(s)
- Shingo Sasaki
- School of Pharmaceutical Sciences, University of Shizuoka , 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
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Reuter C, Huy P, Neudörfl JM, Kühne R, Schmalz HG. Exercises in Pyrrolidine Chemistry: Gram Scale Synthesis of a Pro-Pro Dipeptide Mimetic with a Polyproline Type II Helix Conformation. Chemistry 2011; 17:12037-44. [DOI: 10.1002/chem.201101704] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Indexed: 01/29/2023]
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5
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Higashi T, Isobe Y, Ouchi H, Suzuki H, Okazaki Y, Asakawa T, Furuta T, Wakimoto T, Kan T. Stereocontrolled Synthesis of (+)-Methoxyphenylkainic Acid and (+)-Phenylkainic Acid. Org Lett 2011; 13:1089-91. [DOI: 10.1021/ol103131p] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takumi Higashi
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yoichiro Isobe
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Hitoshi Ouchi
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Hiroto Suzuki
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yuko Okazaki
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Tomohiro Asakawa
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Takumi Furuta
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Toshiyuki Wakimoto
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Toshiyuki Kan
- School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
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6
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Hamashima Y, Sodeoka M. Development of Novel Asymmetric Reactions Based on Acid-base Catalysis of Late Transition Metal Complexes. J SYN ORG CHEM JPN 2011. [DOI: 10.5059/yukigoseikyokaishi.69.972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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7
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Nakamura A, Lectard S, Hashizume D, Hamashima Y, Sodeoka M. Diastereo- and Enantioselective Conjugate Addition of α-Ketoesters to Nitroalkenes Catalyzed by a Chiral Ni(OAc)2 Complex under Mild Conditions. J Am Chem Soc 2010; 132:4036-7. [DOI: 10.1021/ja909457b] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ayako Nakamura
- RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan, Exploratory Research Laboratories, Kyorin Pharmaceutical Co., Ltd., 2399-1, Nogi, Nogi-Machi, Shimotsuga-Gun, Tochigi 329-0114, Japan, and Advanced Technology Support Division, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Sylvain Lectard
- RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan, Exploratory Research Laboratories, Kyorin Pharmaceutical Co., Ltd., 2399-1, Nogi, Nogi-Machi, Shimotsuga-Gun, Tochigi 329-0114, Japan, and Advanced Technology Support Division, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Daisuke Hashizume
- RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan, Exploratory Research Laboratories, Kyorin Pharmaceutical Co., Ltd., 2399-1, Nogi, Nogi-Machi, Shimotsuga-Gun, Tochigi 329-0114, Japan, and Advanced Technology Support Division, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yoshitaka Hamashima
- RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan, Exploratory Research Laboratories, Kyorin Pharmaceutical Co., Ltd., 2399-1, Nogi, Nogi-Machi, Shimotsuga-Gun, Tochigi 329-0114, Japan, and Advanced Technology Support Division, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Mikiko Sodeoka
- RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan, Exploratory Research Laboratories, Kyorin Pharmaceutical Co., Ltd., 2399-1, Nogi, Nogi-Machi, Shimotsuga-Gun, Tochigi 329-0114, Japan, and Advanced Technology Support Division, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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D'hooghe M, Aelterman W, De Kimpe N. A new entry into cis-3-amino-2-methylpyrrolidines viaring expansion of 2-(2-hydroxyethyl)-3-methylaziridines. Org Biomol Chem 2009; 7:135-41. [DOI: 10.1039/b816617j] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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da Silva KP, Godoi MN, Correia CRD. Regio- and Stereoselective Heck Arylations of N-Carbomethoxy-l- 3-Dehydroproline Methyl Ester with Arenediazonium Salts. Total Synthesis of Neuroexcitatory Aryl Kainoids. Org Lett 2007; 9:2815-8. [PMID: 17590003 DOI: 10.1021/ol070980t] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Heck arylation of N-carbomethoxy-L-3-dehydroproline methyl ester with arenediazonium tetrafluoroborates produced chiral 4-aryldehydroproline derivatives in moderate to good yields in a highly regio- and stereocontrolled fashion. A rationale for the unexpected high regioselectivity is provided using Deeth's model. Heck adduct 15 (G = o-CH3O) was converted into several aryl kainoids using concise and efficient routes.
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Affiliation(s)
- Kezia Peixoto da Silva
- Instituto de Química, Universidade Estadual de Campinas, UNICAMP, C.P. 6154, 13084-971, Campinas, São Paulo, Brazil
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10
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Furuta K, Wang GX, Minami T, Nishizawa M, Ito S, Suzuki M. A simple acromelic acid analog potentially useful for receptor photoaffinity labeling and biochemical studies. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.03.098] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Anderson JC, Whiting M. Total synthesis of (+/-)-kainic Acid with an aza-[2,3]-Wittig sigmatropic rearrangement as the key stereochemical determining step. J Org Chem 2003; 68:6160-3. [PMID: 12895045 DOI: 10.1021/jo030101q] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A flexible route to the kainoid skeleton is exemplified by the synthesis of (+/-)-kainic acid from 3-butyn-1-ol. The route relies on the aza-[2,3]-Wittig sigmatropic rearrangement to efficiently install the relative stereochemistry between C2-C3. The C4 stereocenter was derived from a diastereocontrolled iodolactonization. The aza-[2,3]-Wittig rearrangement potentially allows structural diversity at C3 and the displacement of the tosyloxy group with retention of stereochemistry allows structural diversity at C4. The trans-C2 carboxylic acid functional group was found to be the most important for retention of stereochemistry at C4 upon treatment with a higher order cyano cuprate reagent.
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Affiliation(s)
- James C Anderson
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK.
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12
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A new synthetic method for an acromelic acid analog, a potent neuroexcitatory kainoid amino acid, via photoinduced benzyl radical cyclization. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01817-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Hashimoto K, Matsumoto T, Nakamura K, Ohwada SI, Ohuchi T, Horikawa M, Konno K, Shirahama H. Molecular orbital calculation for the model compounds of kainoid amino acids, agonists of excitatory amino acid receptors. Does the kainoid C4-substituent directly interact with the receptors? Bioorg Med Chem 2002; 10:1373-9. [PMID: 11886801 DOI: 10.1016/s0968-0896(01)00400-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Kainoid amino acids are agonists of the AMPA/kainate receptors and exhibit highly potent neuroexcitatory activity. From the results of extensive structure--activity relationship studies, we previously postulated that the C4-substituent of the kainoid amino acids interacts with an allosteric site of the glutamate receptor with electron-donating character. In order to investigate the mode of action in more detail, molecular orbital calculation for model compounds of the kainoid were performed. The results indicated that the HOMO energy level of the C4-substituent is involved in the potent neuroexcitatory activity, thus supporting our hypothesis.
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Affiliation(s)
- Kimiko Hashimoto
- Department of Chemistry, Faculty of Science, Hokkaido University, 060-0810, Sapporo, Japan.
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14
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Baldwin JE, Pritchard GJ, Williamson DS. The synthesis of 4-arylsulfanyl-substituted kainoid analogues from trans-4-hydroxy-L-proline. Bioorg Med Chem Lett 2000; 10:1927-9. [PMID: 10987419 DOI: 10.1016/s0960-894x(00)00352-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The potent neuroexcitatory activity of kainoid amino acids in the mammalian CNS places new analogues in high demand as tools for neuropharmacological research. A range of 4-arylsulfanyl-substituted kainoids has been synthesised in a parallel fashion via mesylate displacement by a number of aromatic and heteroaromatic thiolates upon (2S,3S,4R)-1-benzoyl-3-tert-butoxycarbonylmethyl-4-methanesulfo nyloxy pyrrolidine-2-carboxylic acid methyl ester 8, which is obtainable in eight steps from trans-4-hydroxy-L-proline 5.
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Affiliation(s)
- J E Baldwin
- The Dyson Perrins Laboratory, University of Oxford, UK.
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15
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Collado I, Ezquerra J, Mateo AI, Pedregal C, Rubio A. Stereocontrolled Synthesis of 5α- and 5β-Substituted Kainic Acids. J Org Chem 1999. [DOI: 10.1021/jo982109j] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Iván Collado
- Centro de Investigación Lilly, S. A. Avda de la Industria, 30. 28108 Alcobendas, Madrid, Spain
| | - Jesús Ezquerra
- Centro de Investigación Lilly, S. A. Avda de la Industria, 30. 28108 Alcobendas, Madrid, Spain
| | - Ana I. Mateo
- Centro de Investigación Lilly, S. A. Avda de la Industria, 30. 28108 Alcobendas, Madrid, Spain
| | - Concepción Pedregal
- Centro de Investigación Lilly, S. A. Avda de la Industria, 30. 28108 Alcobendas, Madrid, Spain
| | - Almudena Rubio
- Centro de Investigación Lilly, S. A. Avda de la Industria, 30. 28108 Alcobendas, Madrid, Spain
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17
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18
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Wee AGH, Liu B, McLeod DD. Steric and Electronic Influences on the Diastereoselectivity of the Rh2(OAc)4-Catalyzed C−H Insertion in Chiral Ester Diazoanilides: Synthesis of Chiral, Nonracemic 4-Substituted 2-Pyrrolidinones. J Org Chem 1998. [DOI: 10.1021/jo971540q] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew G. H. Wee
- Department of Chemistry, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - Baosheng Liu
- Department of Chemistry, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - Douglas D. McLeod
- Department of Chemistry, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
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Rubio A, Ezquerra J, Escribano A, Remuiñán MJ, Vaquero JJ. New enantioselective approach to the total synthesis of (−)-α-Kainic Acid. Tetrahedron Lett 1998. [DOI: 10.1016/s0040-4039(98)00166-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Collado I, Ezquerra J, Mateo AI, Rubio A. Stereocontrolled Synthesis of 4-Substituted (±)-Kainic Acids. J Org Chem 1998. [DOI: 10.1021/jo972123g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Iván Collado
- Centro de Investigación Lilly, S. A. Av. de la Industria, 30. 28108-Alcobendas, Madrid, Spain
| | - Jesús Ezquerra
- Centro de Investigación Lilly, S. A. Av. de la Industria, 30. 28108-Alcobendas, Madrid, Spain
| | - Ana I. Mateo
- Centro de Investigación Lilly, S. A. Av. de la Industria, 30. 28108-Alcobendas, Madrid, Spain
| | - Almudena Rubio
- Centro de Investigación Lilly, S. A. Av. de la Industria, 30. 28108-Alcobendas, Madrid, Spain
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General approach to the synthesis of optically active 2-carboxy-4-[′3-(diethoxyphosphinyl)propyl]-5-alkylperazines (CCP analogues). ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0957-4166(97)00157-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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22
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Maeda H, Kraus GA. A Direct Route to Biologically Active Kainic Acid Analogs. J Org Chem 1997; 62:2314-2315. [PMID: 11671554 DOI: 10.1021/jo962114s] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hiroshi Maeda
- Department of Chemistry, Iowa State University, Ames, Iowa 50011
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23
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Baldwin JE, Bamford SJ, Fryer AM, Rudolph MP, Wood ME. Towards a versatile synthesis of kainoids I: Introduction of the C-3 and C-4 substituents. Tetrahedron 1997. [DOI: 10.1016/s0040-4020(97)00190-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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24
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Baldwin JE, Bamford SJ, Fryer AM, Rudolph MP, Wood ME. Towards a versatile synthesis of kainoids II: Two methods for establishment of C-4 stereochemistry. Tetrahedron 1997. [DOI: 10.1016/s0040-4020(97)00191-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Easton CJ. Free-Radical Reactions in the Synthesis of alpha-Amino Acids and Derivatives. Chem Rev 1997; 97:53-82. [PMID: 11848865 DOI: 10.1021/cr9402844] [Citation(s) in RCA: 196] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher J. Easton
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia
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Ezquerra J, Escribano A, Rubio A, Remuiñán MJ, Vaquero JJ. 4-benzyl-2,3-didehydroprolinate as a homochiral template for michael additions. Synthesis of enantiopure α-allokainoids, β-kainoids, 2,3-methanoprolines and other 3,4-disubstituted prolines. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/0957-4166(96)00336-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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Hashimoto K, Konno K, Shirahama H. Simple Methods for Determining Relative Stereochemistry of Kainoid Amino Acids by (1)H NMR Chemical Shifts. J Org Chem 1996; 61:4685-4692. [PMID: 11667397 DOI: 10.1021/jo960169o] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The kainoid amino acids are biologically important compounds because they show remarkable neuroexcitatory and excitotoxic activities. For exhibiting potent activity, the stereochemical relationship of the substituents on the pyrrolidine ring is crucial. We found simple methods for determining the relative stereochemistry of these compounds on the basis of the (1)H NMR chemical shifts of H-2 and H-4 in D(2)O solution. The signals of H-2 appear at fields higher than 4.2 ppm when the compounds have 2,3-trans stereochemistry whereas, in the 2,3-cis compounds, they appear lower than 4.2 ppm, irrespective of the C-4 substituent. This criterion holds when the solution is in the range of pD 3-8. Moreover, when an epimeric pair at C-2 is available and the spectra are recorded at the same or nearly equal pD, the H-2 chemical shift of the 2,3-trans isomer is higher than that of the corresponding 2,3-cis isomer. Similarly, the relative stereochemistry between C-3 and C-4 can be determined from the chemical shift of H-4. The signals of H-4 of the 3,4-cis isomers appear at lower fields than those of the corresponding 3,4-trans isomers in each pair of C-4 epimers when the spectra are recorded at the same or nearly equal pD. This holds for the compounds bearing an unsaturated substituent at C-4. All these phenomena can be rationalized by the anisotropic effect of the pi-electron system in the C-2 and C-4 substituents.
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Affiliation(s)
- Kimiko Hashimoto
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060, Japan
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(nee Yanagida) MH, Hashimoto K, Shirahama H. Acyclic analogs of kainoids: Their syntheses and depolarizing activities. Tetrahedron 1996. [DOI: 10.1016/0040-4020(95)01058-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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31
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Ezquerra J, Escribano A, Rubio A, Jesús Remuiñán M, JoséVaquero J. New enantioselective approach to α-allokainoids by Michael addition to chiral 4-substituted 2,3-didehydroprolinate. Tetrahedron Lett 1995. [DOI: 10.1016/0040-4039(95)01165-e] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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32
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Synthesis of conformationally restricted analogs of kainic acid. Is the conformation of the C4-substituent of kainoid important to its neuroexcitatory activity? Tetrahedron Lett 1995. [DOI: 10.1016/0040-4039(95)01094-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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34
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Synthesis of sugar pyrrolidine derivatives from methyl 4,6-O-benzylidene-2-deoxy-2-dimethylamino-α-d-altropyranoside N-oxide. Carbohydr Res 1995. [DOI: 10.1016/0008-6215(94)00331-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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35
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Konno K. Biologically active components of poisonous mushrooms. FOOD REVIEWS INTERNATIONAL 1995. [DOI: 10.1080/87559129509541021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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36
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37
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38
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Configurational variants of hydroxyphenylkainoid: their potent depolarizing activities in the rat central nervous system. Bioorg Med Chem Lett 1992. [DOI: 10.1016/s0960-894x(00)80404-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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