| abstract |
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 (la), (lb) and (Ic): |