Synthetic studies of trichloroleucine marine natural products. Michael addition of LiCCl3 to N-crotonylcamphor sultam

Organic Letters

Volumn 1, Issue 13, 1999, Pages 2165-2167

  Brantley, Sarah E ^a   Molinski, Tadeusz F ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001622173     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol991256g     Document Type: Article

References (24)

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2. Fu, X.; Ferreira, M. L. G.; Schmitz, F. J.; Kelly-Borges, M. J. Nat. Prod. 1998, 61, 1226-1231.
3. (a) Sitachitta, N.; Rossi, J.; Roberts, M. A.; Gerwick, W. H.; Fletcher, M. D.; Willis, C. L. J. Am. Chem. Soc. 1998, 120, 7131-7132.
4. (b) Hartung, J. Angew. Chem., Int. Ed. 1999, 38, 1209-1211.
5. Perlmutter, P. Conjugate Addition Reactions in Organic Synthesis; Pergamon: Oxford, 1992; p 373.
6. 3: 1,4-adduct, 60%; Maruoka, K.; Shimada, I.; Imoto, H.; Yamamoto, H. Synlett 1994, 519-520.
7. (b) 2-Cyclopentenone with 2: 1,4-adduct (23%) accompanied by 1,2-adduct (34%); Krebs, J.; Weber, A.; Neuenschwander, M. Chimia 1981, 35(2), 55-57. 2 with enoylphosphoranes, 80-90%,
8. - and addition to crotonates, 3-19%:
9. (d) Dehmlow, E. V.; WIlkenloh, J. Chem. Ber. 1990, 123, 583-587.
10. (e) Dehmlow, E. V. Liebigs Ann. Chem. 1972, 758, 148-154. Addition to acrylate ester, acrylonitrile, vinyl sulfone, ca. 10%:
11. (f) Nerdel, F.; Brodowski, W.; Buddras, J.; Fligge, M.; Weyerstahl, P.; Ulm, K.; Finger, C.; Klamann, D. Chem. Ber. 1968, 101, 1407-1413. Addition to menthyloxy 2(5H)-furanone, 14%
12. - with acrylates, acryonitriles, 18-87%
13. ((h) Shono, T.; Ishifune, M.; Ishige, O.; Uyama, H.; Kashimura, S. Tetrahedron Lett. 1990, 49, 7181-7184).
14. Köbrich, G. Angew. Chem., Int Ed. 1972, 11, 473-485 and references therein.
15. (b) Miller, W. T., Jr.; Whalen, D. M. J. Am. Chem. Soc. 1964, 86, 2089-2091.
16. Prepared by N-acylation of (-)-(1S)-camphor-2,10-sultam with crotonyl chloride (NaH, toluene, 0-25°C, 70%): see ent-3, Vandewalle, M.; van der Eycken, J.; Oppolzer, W.; Vulliod, C. Tetrahedron 1986, 42, 4035-4043.
17. 6) gem dimethyl signals of 4a (δ 0.42, s 3H; 1.01, s, 3H) and 4b (δ 0.39, s, 3H; 0.96, s, 3H).
18. 3 to crotonic acid, Zn reduction) and resolved (+)-5 and (-)-5 by repeated recrystallization of the corresponding (-)-cinchonidine salts (aqueous MeOH).
19. This is consistent with addition of 2 to the metal-chelate-preorganized s-cis conformation of 3: cf. Oppolzer, W.; Kingma, A. J.; Poli, G. Tetrahedron 1989, 45, 479-488.
20. TMSCl is well known to accelerate conjugate addition of cuprates to enones and enoyl derivatives, e.g., Lindstedt, E.-L.; Nilsson, M.; Olsson, T. J. Organomet. Chem. 1987, 334, 255-261 and other citations in ref 4.
21. Inaba, T.; Fujita, M.; Ogura, K. J. Org. Chem. 1991, 56, 1274-1279.
22. 12 and comparative spectroscopic analysis.
23. (a) Lee, G. M.; Molinski, T. F. Tetrahedron Lett. 1992, 33, 7671-7674.
24. (b) Kazlauskas, R.; Murphy, P. T.; Wells, R. J. Tetrahedron Lett. 1978, 4945-4948.