Stereospecific sulfur-mediated cleavage of a spirocyclobutanone: Synthesis of a fully functional precursor to the CP compounds

Angewandte Chemie - International Edition

Volumn 38, Issue 10, 1999, Pages 1485-1488

  Meng, Dongfang ^b   Danishefsky, Samuel J ^a  

^a MEMORIAL SLOAN KETTERING CANCER CENTER   (United States)

^b Och Spine at New York Presbyterian Hospitals   (United States)

Author keywords

Natural products; Polycycles; Synthetic methods

Indexed keywords

2 BUTANONE; CP 225917; CP 263114; CYCLOBUTANONE DERIVATIVE; NATURAL PRODUCT; SPIROCYCLOBUTANONE; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL BOND; CYCLIZATION; DECOMPOSITION; DRUG STRUCTURE; DRUG SYNTHESIS; HYDROXYLATION; ISOMERISM; OXIDATION; REACTION ANALYSIS; STEREOSPECIFICITY; STRUCTURE ACTIVITY RELATION;

EID: 0033577820     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(sici)1521-3773(19990517)38:10<1485::aid-anie1485>3.3.co;2-t     Document Type: Article

References (34)

1. H. Osada, J. Antibiot. 1998, 51, 973.
2. S. L. Schreiber, Bioorg. Med. Chem. 1998, 6, 1127.
3. T. T. Dabrah, T. Kaneko, W. Massefski, Jr., E. B. Whipple, J. Am. Chem. Soc. 1997, 119, 1594.
4. T. T. Dabrah, H. J. Harwood, Jr., L. H. Huang, N. D. Jankovich, T. Kaneko, J.-C. Li, S. Lindsey, P. M. Moshier, T. A. Subashi, M. Therrien, P. C. Watts, J. Antibiot. 1998, 50, 1.
5. Synthetic approaches to l and 2: K. C. Nicolaou, M. W. Harter, L. Boulton, B. Jandeleit, Angew. Chem. 1997, 109, 1243;
6. Angew. Chem. Int. Ed. Engl. 1997, 36, 1194;
7. K. C. Nicolaou, M. H. D. Postema, N. D. Miller, G. Yang, Angew. Chem. 1997, 109, 2922;
8. Angew. Chem. Int. Ed. Engl. 1997, 36, 2821;
9. H. M. L. Davies, R. Calvo, G. Ahmed, Tetrahedron Lett. 1997, 38, 1737;
10. P. W. M. Sgarbi, D. L. J. Clive, Chem. Commun. 1997, 2157;
11. A. Armstrong, T. J. Critchley, A. A. Mortlook, Synlett 1998, 552;
12. N. I. Waizumi, T. Ito, T. Fukuyama, Tetrahedron Lett. 1998, 39, 6015;
13. C. Chen, M. E. Layton, M. D. Shair, J. Am. Chem. Soc. 1998, 120, 10784;
14. M. M. Bio, J. L. Leighton, J. Am. Chem. Soc. 1999, 121, 890;
15. K. C. Nicolaou, P. S. Baran, R. Jautelat, Y. He, K. C. Fong, H.-S. Choi, W. H. Yoon, Y.-L. Zhong, Angew. Chem. 1999, 111, 532;
16. Angew. Chem. Int. Ed. 1999, 38, 549.
17. O. Kwon, D.-S. Su, D. Meng, W. Deng, D. D'Amico, S. J. Danishefsky, Angew. Chem. 1998, 110, 1978;
18. Angew. Chem. Int. Ed. 1998, 37, 1877;
19. O. Kwon, D.-S. Su, D. Meng, W. Deng, D. D'Amico, S. J. Danishefsky, Angew. Chem. 1998, 110, 1981;
20. Angew. Chem. Int. Ed. 1998, 37, 1880;
21. A. J. Frontier, S. J. Danishefsky, G. A. Koppel, D. Meng, Tetrahedron 1998, 54, 12 721.
22. B. M. Trost, M. J. Bogdanowicz, J. Am. Chem. Soc. 1973, 95, 5311;
23. B. M. Trost, M. J. Bogdanowicz, J. Am. Chem. Soc. 1973, 95, 5321;
24. B. M. Trost, J. H. Rigby, J. Org. Chem. 1976, 41, 3217.
25. C. R. Johnson, J. P. Adams, M. P. Braun, C. B. W. Senanayake, Tetrahedron Lett. 1992, 33, 917.
26. Review: N. Miyaura, A. Suzuki, Chem. Rev. 1995, 95, 2457.
27. For a recent application of a B-alkyl Suzuki coupling in a complex context, see D. Meng, P. Bertinato, A. Balog, D.-S. Su, T. Kamenecka, E. J. Sorensen, S. J. Danishefsky, J. Am. Chem. Soc. 1997, 119, 10073.
28. The sequence started with hydroboration of 1-benxyloxy-5-hexene with diborane (alkene:diborane ≈ 4:1) in THF. The resultant solution was transferred to the reaction system for Suzuki coupling.
29. A. Hosomi, H. Sakurai, J. Am. Chem. Soc. 1977, 99, 1673.
30. The extent of actual conjugation of the C7 oxo group with the bridgehead double bond is not clear. In NMR spectra, the chemical shift of the C5 proton in the enone suggests some conjugation.
31. Review: S. H. Pine, Org. React. 1993, 43, 1.
32. Review: J. A. Hyatt, P. W. Raynolds, Org. React. 1994, 45, 159.
33. The osmylation product emerges as a complex mixture of ring and chain tautomers, which is further complicated by the existence of phenylsulfanyl epimers. Full purification is achieved only at the stage of 28 or 29.
34. Analysis of the NMR spectrum of aldehyde 29 suggests that the formyl group at C12 is in the α position. The stereochemical assignment for 2 presented the C13 oxo group as being in the β position. The stereochemical relationships between the two CP natural products at C12 have not been rigorously defined. These matters, as well as the order of thermodynamic stabilities at C12, will require further research.