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Fernández-Mateos A, Ramos Silvo AI, Rubio González R, Simmonds MSJ. Synthesis of CDE molecular fragments related to sendanin mediated by titanocene(III). Org Biomol Chem 2012; 10:5620-8. [PMID: 22717555 DOI: 10.1039/c2ob25538c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A practical, brief, and diastereoselective synthesis of limonoid CDE fragments from a readily available starting material is described. The key step was the titanocene(III)-promoted cyclization of unsaturated epoxylactones, readily prepared from α-cyclocitral. In this way, we confirm the viability of our procedure for the synthesis of a limonoid model with different functionalization patterns. We also report the antifeedant activity of epoxylactones 18 and 19, which show significant antifeedant activity against Spodoptera littoralis and Spodoptera frugiperda, two insect species with different feeding ecologies.
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Affiliation(s)
- A Fernández-Mateos
- Departamento de Química Orgánica, Facultad de CC. Químicas, Universidad de Salamanca, Plaza de los Caídos 1-5, 37008, Salamanca, Spain.
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Nakai Y, Tepp WH, Dickerson TJ, Johnson EA, Janda KD. Function-oriented synthesis applied to the anti-botulinum natural product toosendanin. Bioorg Med Chem 2008; 17:1152-7. [PMID: 19131252 DOI: 10.1016/j.bmc.2008.12.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 12/10/2008] [Accepted: 12/14/2008] [Indexed: 10/21/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the etiological agents responsible for botulism, a disease characterized by peripheral neuromuscular blockade and a characteristic flaccid paralysis of humans. The natural product toosendanin is a traditional Chinese medicine which has been reported to have anti-botulinum properties in animal models. To establish what chemical functionalities are necessary for the anti-botulinum properties found within toosendanin, a study was initiated with the goal of using function-oriented synthesis (FOS) as a strategy to begin to unravel toosendanin's powerful anti-botulinum properties. From these studies a new synthetic strategy is put forth allowing access to a 4-acetoxy CD fragment analogue (14) of toosendanin, which was achieved from mesityl oxide and acetylacetone in 14 steps. Animal studies on this fragment are also reported.
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Affiliation(s)
- Yuya Nakai
- Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Paquette LA, Hong FT. Total synthesis of dumsin. 1. Retrosynthetic strategy and the elaboration of key intermediates from (--)-bornyl acetate. J Org Chem 2003; 68:6905-18. [PMID: 12946130 DOI: 10.1021/jo0301346] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An intramolecular anionic oxy-Cope rearrangement (44 --> 46) serves as the key step in a synthetic approach to the insect antifeedant dumsin. Initial investigations clarified the manner in which (--)-bornyl acetate may be transformed into the exo-norbornenol 44. Two routes were developed to advance beyond 46. The first involved acetal 51 as a matrix that was expected to allow the elaboration of rings D and E. The second plan deferred oxidation of the cyclopentene ring in 46 to a later stage of molecular construction. The latter experiments formed the basis of a protocol that led to the successful acquisition of keto aldehydes typified by 108 and 114.
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Affiliation(s)
- Leo A Paquette
- Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, USA.
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Mateos AF, Martín de la Nava EM, González RR. A stereoselective synthesis of (+/-)-C-secolimonoid BCDE model compounds related to the insect antifeedant ohchinolide. J Org Chem 2001; 66:7632-8. [PMID: 11701014 DOI: 10.1021/jo010449q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A short and stereoselective synthesis of a (+/-)-BCDE C-secolimonid model insect antifeedant related to ohchinolide and nimbolidin was accomplished in 13 (30% overall yield) and 15 (30% overall yield) steps, respectively, from ethyl drimanate. The key steps are the torquoselective electrocyclization of the divinyl ketone 6, induced by perchloric acid, and the stereoselective rearrangement of the hydroxy lactone 12, inspired in a biosynthetic proposal. An alternative route, which provides access to (+/-)-BCDE ohchinolide and nimbolidin isomers, is also described.
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Affiliation(s)
- A F Mateos
- Universidad de Salamanca, Facultad de C. Químicas, Departamento de Química Orgánica, Plaza de los Caídos 1-5, 37008 Salamanca, Spain.
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Fernández-Mateos A, Martín de la Nava EM, Pascual Coca G, Rubio González R, Ramos Silvo AI, Simmonds MSJ, Blaney WM. Synthesis of Active Antifeedant CDE Fragments of 11-Ketoepoxyazadiradione Based on an Electrocyclization Reaction Catalyzed by Perchloric Acid. J Org Chem 1998. [DOI: 10.1021/jo981456q] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alfonso Fernández-Mateos
- Facultad de C. Químicas, Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1−5, 37008 Salamanca, Spain, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U.K., and Department of Biology, Birkbeck College, Malet Street, London, U.K
| | - Eva M. Martín de la Nava
- Facultad de C. Químicas, Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1−5, 37008 Salamanca, Spain, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U.K., and Department of Biology, Birkbeck College, Malet Street, London, U.K
| | - Gustavo Pascual Coca
- Facultad de C. Químicas, Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1−5, 37008 Salamanca, Spain, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U.K., and Department of Biology, Birkbeck College, Malet Street, London, U.K
| | - Rosa Rubio González
- Facultad de C. Químicas, Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1−5, 37008 Salamanca, Spain, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U.K., and Department of Biology, Birkbeck College, Malet Street, London, U.K
| | - Ana I. Ramos Silvo
- Facultad de C. Químicas, Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1−5, 37008 Salamanca, Spain, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U.K., and Department of Biology, Birkbeck College, Malet Street, London, U.K
| | - M. S. J. Simmonds
- Facultad de C. Químicas, Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1−5, 37008 Salamanca, Spain, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U.K., and Department of Biology, Birkbeck College, Malet Street, London, U.K
| | - W. M. Blaney
- Facultad de C. Químicas, Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1−5, 37008 Salamanca, Spain, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U.K., and Department of Biology, Birkbeck College, Malet Street, London, U.K
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