| abstract |
The invention relates to an improved process for the preparation of a macrocyclic compound of formula I n n n wherein R 1 , R 2 , R 3 , A and D have the meaning given in the claims; by a ring closure metathesis of the corresponding diene of formula III n n n wherein R 1 , R 2 , R 3 , A and D′ have the meaning given in the claims; in the presence of a benzylidene ruthenium catalyst, wherein the phenyl group is substituted by a nitro group. |