PROCESSES FOR THE PREPARATION OF 5-AZASPIRO[2.4]HEPTANE-6-CARBOXYLIC ACID AND ITS DERIVATIVES

摘要

The present invention relates generally to an improved process for the preparation of 5-azaspiro[2.4]heptane-6-carboxylic acid and its derivatives which are useful intermediates in the synthesis of biologically active molecules, especially in the synthesis of hepatits C virus NS5A inhibitors. In particular, the present invention relates to processes and intermediates for the preparation of compounds of formulae (Ia), (Ib) and (Ic):