The total synthesis of the novel immunosuppressant sanglifehrin A (SFA, 1)
is described. The approach is flexible, convergent, and stereoselective. Th
e use of Paterson's aldol methodology was pivotal fur the preparation of th
e novel, highly substituted spirolactam fragment of SFA. The 22-membered ma
crocyclic core of the molecule and the coupling of this fragment to the spi
rolactam moiety were successfully achieved using selective intra- and inter
molecular Stille reactions, respectively. Carbodiimide-based protocols were
employed for the synthesis of the tripeptide backbone.