A series of potential antimicrobial derivatives possessing bioisosteric replacements for the central oxazolidinone ring found in oxazolidinone antibacterials have been prepared. The design concept involved replacement of the requisite sp3-hybridized stereogenic center found at the 5-position of the oxazolidinone with a nitrogen atom. The synthesis and antibacterial activity of three such ring systems, the benzisoxazolinones, pyrroles, and ...