PROCESS FOR PREPARATION OF CYCLOSPORIN A ANALOGUES HAVING A TERMINAL DIENE GROUP

摘要

The invention is concerned with a new process for the preparation of a cyclosporin A analog of formula I comprising, a) allylating a protected cyclosporin A aldehyde with a allylmetal reagent and, b) converting the compound obtained in step a) to the cyclosporin A analog of formula I. In particular, the allyl reagent is a trimethylsilyl-allyl borate ester or a trimethylsilyl-allyl organometallic compound containing aluminium or titanium.