A catalytic enantioselective synthesis of the endothelin receptor antagonists SB-209670 and SB-217242. A base-catalyzed stereospecific formal 1,3-hydrogen transfer of a chiral 3-arylindenol

Journal of the American Chemical Society

Volumn 120, Issue 18, 1998, Pages 4550-4551

  Clark, William M ^a   Tickner Eldridge, Ann M ^a   Kris Huang, G ^a   Pridgen, Lendon N ^a   Olsen, Mark A ^a   Mills, Robert J ^a   Lantos, Ivan ^a   Baine, Neil H ^a  

^a GLAXOSMITHKLINE   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001013911     PISSN: 00027863     EISSN: 15205126     Source Type: Journal    
DOI: 10.1021/ja973882j     Document Type: Letter

References (18)

1. Yanagisawa, M.; Kurihara, H.; Kimura, S.; Tomobe, Y.; Kobayashi, M.; Mitsui, Y.; Yazaki, Y.; Goto, K.; Masaki, T. Nature 1988, 332, 411.
2. Lago, M. A.; Luengo, J. I.; Peishoff, C. E.; Elliot, J. D. In. Annual Reports in Medicinal Chemistry; Bristol, J. A., Ed.; Academic: San Diego, 1.996; Vol. 31, p 81.
3. Endothelin Receptors: From the Gene to the Human; Ruffolo, R. R., Jr., Ed.; CRC: Boca Raton, 1995.
4. Elliot, J. D.; Lago, M. A.; Cousins, R. D.; Gao, A.; Leber, J. D.; Erhard, K. F.; Nambi, P.; Elshourbagy, N. A.; Kumar, C.; Lee, J. A.; Bean, J. W.; DeBrosse, C. W.; Eggleston, D. S.; Brooks, D. P.; Feuerstein, G.; Ruffolo, R. R., Jr.; Weinstock, J.; Gleason, J. G.; Peishoff, C. E.; Ohlstein, E. H. J. Med. Chem. 1994, 37, 1553.
5. (a) Itsuno, S.; Ito, K.; Hirao, A.; Nakahama, S. Bull. Chem. Soc. Jpn. 1987, 60, 395.
6. (b) Corey, E. J.; Bakshi, R. K.; Shibata, S. J. Am. Chem. Soc. 1987, 109, 5551 and references therein.
7. (a) Motherwell, W. B.; Sandham, D. A. Tetrahedron Lett. 1992, 33, 6187. For related examples, see
8. (b) Edwards, G. L.; Motherwell, W. B.; Powell, D. M.; Sandham, D. A. J. Chem. Soc., Chem. Commun. 1991, 1399.
9. Anti β-hydrogen addition and/or elimination pathways are relatively uncommon in nickel and palladium chemistry-a pathway which would lower the stereoselectivity of 5 → 6; see: Cross, R. J. In The Chemistry of the MetalCarbon Bond; Hartley, S. P. F. R., Ed.; John Wiley: New York, 1985; Vol. 2, p 559.
10. Bisarya, S. C.; Rao, R. Synth. Commun. 1993, 23, 779.
11. To the best of our knowledge, this is the first example of a palladiumcatalyzed 5-endo-trig cyclization to form a 2H-indenone. For examples of palladium-catalyzed and transition metal based transformations for the synthesis of indenones, see: (a) Larock, R. C.; Doty, M. J.; Cacchi, S. J. Org. Chem. 1993, 58, 4579 and references therein.
12. Chen, C.-Y.; Lieberman, D. R.; Larsen, R. D.; Verhoeven, T. R.; Reider, P. J. J. Org. Chem. 1997, 62, 2676.
13. A reduction in the optical purity of 5 (94% ee) was not observed with the potassium alkoxide when quenched with glacial AcOH after 50% conversion. Therefore carbanion formation did not contribute to the dramatic loss of stereochemistry observed in this reaction.
14. The DABCO-catalyzed rearrangement was equally efficient in the absence of light, ruling out a photochemical, rearrangement. For examples of 1,5-sigmatropic migrations of alkenyl and aryl groups of 2,3-phenylindenol and 2,3,4,5-tetraphenylcyclopentenol, see: Battye, P. J.; Jones, D. W. J. Chem. Soc., Chem. Commun. 1984, 990.
15. Dramatic rate acceleration of potassium alkoxides on 1,5-hydrogen rearrangements has also been reported: Paqnette, L. A.; Crouse, G. D.; Sharma, A. K. J. Am. Chem. Soc. 1980, 102, 3972.
16. Using a stoichiometric amount of base, piperidine and tributylamine delivered 6 in 92% yield (88.7% ee) and 90% yield (91.7% ee), respectively.
17. The percent deuterium incorporation of 8 and 10 was determined by flow injection analysis electrospray ionization mass spectrometry using successive normalization subtraction of the observed ion patterns of the labeled and unlabeled compounds.
18. Pettit, W. A.; Wilson, J. W. J. Am. Chem. Soc. 1977, 99, 6372.