Stereospecific synthesis of oximes and oxime ethers of 3-azabicycles: A SAR study towards antimicrobial agents

Libraries of 1- and 7-methyl-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones/oximes/ O-methyloximes were synthesized and unambiguously characterized by 1D/2D NMR and single crystal XRD data. All the synthesized oximes and oxime ethers were evaluated for their in vitro antimicrobial activity. Libraries of 1-methyl-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones/oximes/ O-methyloximes 1–14/15–28/29–42 and 7-methyl-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones/oximes/ O-methyloximes 43–48/49–54/55–60 were synthesized and their stereochemistry was established by 1D/2D NMR spectral and single crystal XRD studies. All the synthesized oximes and oxime ethers were screened for their in vitro antimicrobial activity against a panel of pathogenic bacteria ( Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa) and fungi ( Candida albicans, Candida parapsilosis, Aspergillus niger and Cryptococcus neoformans) using Gentamicin and Fluconazole as standards, respectively. From the SAR profile, the lead molecules were identified.