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Understanding the Domino Retro [3+2] Cycloaddition/cyclization Reaction of Bicyclic Isoxazolidines in the Synthesis of Spirocyclic Alkaloids. A DFT Study

Overview
Journal J Mol Model
Publisher Springer
Specialty Molecular Biology
Date 2014 Jul 10
PMID 25005002
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Abstract

The domino retro [3+2] cycloaddition/cyclization reaction of bicyclic isoxazolidines 4 yielding [6.6.5]-tricyclic isoxazolidines 7 and [6.5.5]-tricyclic isoxazolidines 8, experimentally reported by Holmes et al., has been studied in toluene using DFT methods at the MPWB1K/6-311G** level. This domino reaction begins by a reto [3+2] cycloaddition reaction of the bicyclic isoxazolidines 4 forming the cyclic nitrones 5, which undergo a subsequent cyclization reaction yielding [6.6.5]-tricyclic isoxazolidines 7 or [6.5.5]-tricyclic isoxazolidines 8. The [3+2] cycloaddition reactions of cyclic nitrone 12 with ethylene 13, and with (Z)-but-2-enenitrile 15 were also studied in order to explain the role of the tether in the cyclization step. The present study shows that, unlike the [3+2] cycloaddition reaction of cyanoalkene 15, the cyano group in the cyclization step does not have any effect on the selectivity. The present study suggests that the presence of the BF3 catalyst in the domino reaction can change the formation of the [6.5.5]-tricyclic isoxazolidine 7 to the [6.6.5]-tricyclic isoxazolidine 8.

References
1.
Tufariello J, Trybulski E . A synthetic approach to the skeleton of histrionicotoxin. J Org Chem. 1974; 39(23):3378-84. DOI: 10.1021/jo00937a016. View

2.
Griffith G, Hillier I, Moralee A, Percy J, Roig R, Vincent M . Interplay of structure and reactivity in a most unusual furan Diels-Alder reaction. J Am Chem Soc. 2006; 128(40):13130-41. DOI: 10.1021/ja061458p. View

3.
Lee , Yang , PARR . Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Phys Rev B Condens Matter. 1988; 37(2):785-789. DOI: 10.1103/physrevb.37.785. View

4.
Coote S, Moore S, OBrien P, Whitwood A, Gilday J . Organolithium-mediated conversion of beta-alkoxy aziridines into allylic sulfonamides: effect of the N-sulfonyl group and a formal synthesis of (+/-)-perhydrohistrionicotoxin. J Org Chem. 2008; 73(19):7852-5. DOI: 10.1021/jo801586h. View

5.
Daly J, Karle I, MYERS C, Tokuyama T, Waters J, WITKOP B . Histrionicotoxins: roentgen-ray analysis of the novel allenic and acetylenie spiroalkaloids isolated from a Colombian frog, Dendrobates histrionicus. Proc Natl Acad Sci U S A. 1971; 68(8):1870-5. PMC: 389311. DOI: 10.1073/pnas.68.8.1870. View