Strange formation of N-hydroxy-3,3-dimethyl-2,6-diarylpiperidin-4-one and its oxime derivative--synthesis, stereochemistry, antibacterial and antifungal activity.

OBJECTIVES AND METHODS A collection of novel N-hydroxy-3,3-dimethyl-2,6-diarylpiperidin-4-one oximes 28-32 are synthesized, characterized by melting point, elemental analysis, MS, FT-IR, one-dimensional NMR (1H & 13C) and two dimensional Noesy spectroscopic data and evaluate for their in vitro antibacterial and antifungal activities. RESULTS AND CONCLUSION Compound 32, exerted a wide range of antibacterial activities against the entire tested gram-positive and gram-negative bacterial strains except Escherichia coli, besides compound 30, which is more active against Klebsiella pneumoniae, a gram-negative coccus. Compound 29 exerted strong antifungal activities against Aspergillus flavus and Microsporum gypseum. In addition, compound 32 is more potent against Rhizopus.