Synthesis of 5-phenylproline derivatives with antibacterial activity

Methyl esters of 5-phenylprolines with the vinylsulfonyl or cyano group in the 4-position of the pyrrolidine ring have been synthesized. X-ray crystallography shows that all substituents in the vinylsulfonyl derivatives are cis to each other. All compounds are inhibitors of Staphylococcus aureus sortase SrtA.