Synthesis of novel potent hepatitis C virus NS3 protease inhibitors: Discovery of 4-hydroxy-cyclopent-2-ene-1,2-dicarboxylic acid as a N-acyl-l-hydroxyproline bioisostere

HCV NS3 protease inhibitors incorporating 4-hydroxy-cyclopent-2-ene-1,2-dicarboxylic acid as a new N-acyl-l-hydroxyproline mimic are described. The most promising exhibiting a Ki value of 1.1 nM.