Stereocontrolled total synthesis of bengazole A: A marine bisoxazole natural product displaying potent antifungal properties

Angewandte Chemie - International Edition

Volumn 45, Issue 40, 2006, Pages 6714-6718

  Bull, James A ^a   Balskus, Emily P ^a   Horan, Richard A J ^a   Langner, Martin ^a   Ley, Steven V ^a  

^a UNIVERSITY OF CAMBRIDGE   (United Kingdom)

Author keywords

Antifungal agents; Cycloaddition; Heterocycles natural products; Total synthesis

Indexed keywords

ANTIFUNGAL AGENTS; CYCLOADDITION; HETEROCYCLES NATURAL PRODUCTS; TOTAL SYNTHESIS;

ADDITION REACTIONS; CATALYST SELECTIVITY; ISOMERS; STEREOCHEMISTRY; SUBSTITUTION REACTIONS; SYNTHESIS (CHEMICAL);

NITROGEN COMPOUNDS;

ANTIFUNGAL AGENT; MICONAZOLE; OXAZOLE DERIVATIVE;

ARTICLE; BIOLOGY; CANDIDA ALBICANS; CHEMISTRY; DRUG EFFECT; MARINE BIOLOGY; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; STEREOISOMERISM; SYNTHESIS; X RAY CRYSTALLOGRAPHY;

ANTIFUNGAL AGENTS; CANDIDA ALBICANS; CRYSTALLOGRAPHY, X-RAY; MAGNETIC RESONANCE SPECTROSCOPY; MARINE BIOLOGY; MICONAZOLE; OXAZOLES; STEREOISOMERISM;

EID: 33750160748     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200602050     Document Type: Article

References (64)

1. a) J. R. Lewis, Nat. Prod. Rep. 2002, 19, 223;
2. b) Z. Jin, Z. Li, R. Huang, Nat. Prod. Rep. 2002, 19, 454, and references therein.
3. a) V. S. C. Yeh, Tetrahedron 2004, 60, 11995;
4. b) Y. Hamada, T. Shioiri, Chem. Rev. 2005, 105, 4441;
5. c) P. Wipf, Chem. Rev. 1995, 95, 2115;
6. d) P. Wipf, S. Venkatraman, Synlett 1997, 1;
7. e) L. O. Haustedt, I. V. Hartung, H. M. R. Hoffmann, Angew. Chem. 2003, 115, 2815;
8. Angew. Chem. Int. Ed. 2003, 42, 2711; ;
9. f) E. Riego, D. Hernández, F. Albericio, M. Álvarez, Synthesis 2005, 1907, and references therein.
10. P. A. Searle, T. F. Molinski, J. Am. Chem. Soc. 1995, 117, 8126.
11. R. Jansen, H. Irschik, H. Reichenbach, V. Wray, G. Höfle, Liebigs Ann. Chem. 1994, 759.
12. T. Ichiba, W. Y. Yoshida, P. J. Scheuer, T. Higa, D. G. Gravalos, J. Am. Chem. Soc. 1991, 113, 3173.
13. N. Lindquist, W. Fenical, G. D. Van Duyne, J. Clardy, J. Am. Chem. Soc. 1991, 113, 2303.
14. A. Nagatsu, H. Kajitani, J. Sakakibara, Tetrahedron Lett. 1995, 36, 4097.
15. M. Adamczeski, E. Quiñoà, P. Crews, J. Am. Chem. Soc. 1988, 110, 1598.
16. a) J. Rodríguez, R. M. Nieto, P. Crews, J. Nat. Prod. 1993, 56, 2034;
17. b) A. Rudi, Y. Kashman, Y. Benayahu, M. Schleyer, J. Nat. Prod. 1994, 57, 829;
18. c) A. Groweiss, J. J. Newcomer, B. R. O'Keefe, A. Blackman, M. R. Boyd, J. Nat. Prod. 1999, 62, 1691;
19. d) R. Fernández, M. Dherbomez, Y. Letourneux, M. Nabil, J. F. Verbist, J. F. Biard, J. Nat. Prod. 1999, 62, 678.
20. P. A. Searle, R. K. Richter, T. F. Molinski, J. Org. Chem. 1996, 61, 4073.
21. T. F. Molinski, J. Nat. Prod. 1993, 56, 1.
22. J. Antonio, T. F. Molinski, J. Nat. Prod. 1993, 56, 54.
23. a) R. J. Mulder, C. M. Shafer, T. F. Molinski, J. Org. Chem. 1999, 64, 4995;
24. b) C. M. Shafer, T. F. Molinski, Tetrahedron Lett. 1998, 39, 2903.
25. C. M. Shafer, T. F. Molinski, Heterocycles 2000, 53, 1167.
26. a) J. C. Hodges, W. C. Patt, C. J. Connolly, J. Org. Chem. 1991, 56, 449;
27. b) E. Vedejs, S. D. Monahan, J. Org. Chem. 1996, 61, 5192.
28. P. Chittari, Y. Hamada, T. Shioiri, Heterocycles 2003, 59, 465.
29. P. Chittari, Y. Hamada, T. Shioiri, Synlett 1998, 1022.
30. a) J. S. Barlow, D. J. Dixon, A. C. Foster, S. V. Ley, D. J. Reynolds, J. Chem. Soc. Perkin Trans. 1 1999, 1627;
31. b) D. J. Dixon, A. C. Foster, S. V. Ley, D. J. Reynolds, J. Chem. Soc. Perkin Trans. 1 1999, 1631;
32. c) S. V. Ley, D. K. Baeschlin, D. J. Dixon, A. C. Foster, S. J. Ince, H. W. M. Priepke, D. J. Reynolds, Chem. Rev. 2001, 101, 53;
33. d) P. Michel, S. V. Ley, Angew. Chem. 2002, 114, 4054;
34. Angew. Chem. Int. Ed. 2002, 41, 3898;.
35. a) U. Schöllkopf, R. Schröder, Angew. Chem. 1971, 83, 358;
36. Angew. Chem. Int. Ed. Engl. 1971, 10, 333;
37. b) A. M. van Leusen, B. E. Hoogenboom, H. Siderius, Tetrahedron Lett. 1972, 2369.
38. The yield of the amide coupling to form amide 3 is highly dependent on the quality of carboxylic acid 9, which is unstable and decomposes on storage. A more practical route on a large scale generates acid 9 through hydrolysis of the equivalent non-enantiopure methyl ester. The coupling with the enantiopure serine methyl ester resolves the acid into diastereomers, which are easily separated by column chromatography to provide amide 3 as a single stereoisomer.
39. For oxazole-forming reactions using (diethylamino)sulfur trifluoride (DAST), see: a) W. J. Middleton, J. Org. Chem. 1975, 40, 574;
40. b) P. Lafargue, P. Guenot, J.-P. Lellouche, Heterocycles 1995, 41, 947;
41. c) A. J. Phillips, Y. Uto, P. Wipf, M. J. Reno, D. R. Williams, Org. Lett. 2000, 2, 1165;
42. for reactions in which the Burgess reagent is used, see: d) G. M. Atkins, Jr., E. M. Burgess, J. Am. Chem. Soc. 1968, 90, 4744;
43. e) P. Wipf, C. P. Miller, Tetrahedron Lett. 1992, 33, 907;
44. for selected other methods, see: f) A. Sakakura, R. Kondo, K. Ishihara, Org. Lett. 2005, 7, 1971;
45. g) P. Wipf, C. P. Miller, Tetrahedron Lett. 1992, 33, 6267.
46. D. R. Williams, P. D. Lowder, Y.-G. Gu, D. A. Brooks, Tetrahedron Lett. 1997, 38, 331.
47. N. Endoh, K. Tsuboi, R. Kim, Y. Yonezawa, C.-G. Shin, Heterocycles 2003, 60, 1567.
48. D. B. Dess, J. C. Martin, J. Am. Chem. Soc. 1991, 113, 7277.
49. J. S. Panek, R. T. Beresis, J. Org. Chem. 1996, 61, 6496.
50. a) P. Wipf, C. P. Miller, J. Org. Chem. 1993, 58, 3604;
51. b) P. Wipf, S. Lim, J. Am. Chem. Soc. 1995, 117, 558.
52. -1, 24°C, λ = 215 nm, retention times: (S)-C10 isomer 10.35 min, (R)-C10 isomer 11.85 min).
53. 3N in place of 2,6-di-tert-butylpyridine from the start of the reaction again provided bisoxazole 12 as a single enantiomer. However, these conditions gave a yield of only 47% and a reduced reaction time, thus suggesting a different reaction pathway.
54. -1 at 100 bar, 35°C, λ = 210 nm, retention times: (S)-C10 isomer 8.66 min, (R)-C10 isomer 9.08 min).
55. J. M. Gardiner, N. R. Panchal, W. T. Stimpson, J. M. Herbert, G. J. Ellames, Synlett 2005, 2685.
56. a) A. P. Kozikowski, A. K. Ghosh, J. Am. Chem. Soc. 1982, 104, 5788;
57. b) A. P. Kozikowski, A. K. Ghosh, J. Org. Chem. 1984, 49, 2762;
58. c) V. Jäger, R. Schohe, E. F. Paulus, Tetrahedron Lett. 1983, 24, 5501.
59. a) K. N. Houk, S. R. Moses, Y.-D. Wu, N. G. Rondan, V. Jäger, R. Schohe, F. R. Fronczek, J. Am. Chem. Soc. 1984, 106, 3880;
60. b) K. N. Houk, H.-Y. Duh, Y.-D. Wu, S. R. Moses, J. Am. Chem. Soc. 1986, 108, 2754.
61. D. P. Curran, J. Am. Chem. Soc. 1983, 105, 5826.
62. 1HNMR spectra of our synthetic material.
63. +: 525.3176, found: 525.3163.
64. We observed no racemization at the C10 atom on storage of synthetic bengazole A under argon at -20°C over a period of one month.