Synfacts 2009(9): 0950-0950  
DOI: 10.1055/s-0029-1217618
Synthesis of Natural Products and Potential Drugs
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of (-)-PNU-286607

Contributor(s): Philip Kocienski
J. C. Ruble, A. R. Hurd*, T. A. Johnson, D. A. Sherry, M. R. Barbachyn, P. L. Toogood, G. L. Bundy, D. R. Graber, G. M. Kamilar
Pharmacia Corporation, Kalamazoo, Pfizer Global Research and Development, Ann Arbor and Pfizer Global Research and Development, Groton, USA
Further Information

Publication History

Publication Date:
21 August 2009 (online)

Significance

PNU-286607 is an antibiotic that inhibits bacterial DNA gyrase and displays little cross-resistance to current commercial antibiotics. It is active against MRSA and fluoroquinoline-resistant bacterial strains. The key step in this ­elegant asymmetric synthesis is a 1,5-hydrogen shift of the alkylidene barbiturate E to generate an iminium salt intermediate that undergoes spiro­cyclization.