A preliminary evaluation of a metathesis approach to bryostatins

Tetrahedron Letters

Volumn 47, Issue 13, 2006, Pages 2223-2227

  Ball, Matthew ^a   Bradshaw, Benjamin J ^a   Dumeunier, Raphaël ^a   Gregson, Thomas J ^a   MacCormick, Somhairle ^a   Omori, Hiroki ^a   Thomas, Eric J ^a  

^a UNIVERSITY OF MANCHESTER   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ALKENE; BRYOSTATIN; ESTER; MACROLIDE; METHYL GROUP;

ARTICLE; COVALENT BOND; DEBENZYLATION; DRUG SYNTHESIS; HYDROXYLATION; METHYLATION; OXIDATION; PRECURSOR; RING CLOSING METATHESIS;

EID: 33344473590     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2006.01.097     Document Type: Article

References (22)

1. R. Mutter, and M. Wills Bioorg. Med. Chem. 8 2000 1841
2. K.J. Hale, M.G. Hummersone, S. Manaviazar, and M. Frigero Nat. Prod. Reports 19 2002 413
3. S. Masamune Pure Appl. Chem. 60 1988 1587
4. M. Kageyama, T. Tamura, M.H. Nantz, J.C. Roberts, P. Somfrai, D.C. Whitenour, and S. Masamune J. Am. Chem. Soc. 112 1990 7407
5. D.A. Evans, P.H. Carter, E.M. Carreira, J.A. Prunet, A.B. Charette, and M. Lautens Angew. Chem., Int. Ed. 37 1998 2354
6. D.A. Evans, P.H. Carter, E.M. Carreira, J.A. Prunet, A.B. Charette, and M. Lautens J. Am. Chem. Soc. 121 1999 7540
7. K. Ohmori, Y. Ogawa, T. Obitsu, Y. Ishikawa, S. Nishiyama, and S. Yamamura Angew. Chem., Int. Ed. 39 2000 2290
8. P.A. Wender, J. De Brabander, P.G. Harran, J.-M. Jimenez, M.F.T. Koehler, B. Lippa, C.-M. Park, and M. Shiozaki J. Am. Chem. Soc. 120 1998 4534
9. P.A. Wender, J. De Brabander, P.G. Harran, K.W. Hinkle, B. Lippa, and G.R. Pettit Tetrahedron Lett. 39 1998 8625
10. P.A. Wender, and B. Lippa Tetrahedron Lett. 41 2000 1007
11. M. Ball, A. Baron, B. Bradshaw, H. Omori, S. MacCormick, and E.J. Thomas Tetrahedron Lett. 45 2004 8737
12. P. Almendros, A. Rae, and E.J. Thomas Tetrahedron Lett. 41 2000 9565
13. J. Gracia, and E.J. Thomas J. Chem. Soc., Perkin Trans. 1 1998 2853
14. K.C. Nicolaou, P.G. Bulger, and D. Sarlah Angew. Chem., Int. Ed. 44 2005 4490
15. The ee's of the hydroxylactone 14 and the hydroxyepoxides 27 and 38 were shown to be ≥90% and their absolute configurations as shown using the Mosher's method. Full details will be reported in a full paper.
16. Alternative procedures for the stereoselective conversion of aldehyde 18 into the alcohol 19 using enantiomerically enriched reagents were investigated. Full details will be reported in a full paper.
17. An alternative sequence for the synthesis of the ketone 23 based on the stereoselective addition of an allylic Grignard reagent to a conjugated acetylenic ketone has also been developed (cf. Ref. 4). Full details will be reported elsewhere.
18. M. Michalak, and J. Wicha Synlett 2005 2277
19. S.A. Kozmin, T. Iwama, Y. Huang, and V.H. Rawal J. Am. Chem. Soc. 124 2002 4629
20. J.A. Frick, J.B. Klassen, A. Bathe, J.M. Abramson, and H. Rapoport Synthesis 7 1992 621
21. Attempts to convert the hydroxyketone formed on desilylation of ketone 45 into the corresponding methoxy acetal were unsuccessful; the enol ether 46 was the only product which could be isolated.
22. The linear ketone 34 was also desilylated, oxidised to the corresponding carboxylic acid, and esterified using the alcohols 42 and 49. The ester of alcohol 42 lacking the geminal dimethyl groups at C(18) underwent ring-closing metathesis, whereas the ester derived from alcohol 49 did not. These results are consistent with those reported here and will be described elsewhere.