The Zn2+ ion mediated reaction of the 2-cyano-A33-piperidine Sa (X= SO&H5) with the silyl enol ether of Na-methyl-2-acetylindole (24) led to formation of compounds 29a, b (70%) resulting from introduction of the acetylindole moiety at the exocyclic (C-7) carbon center and migration of the phenylsulfonyl group from C-7 to C-4. In contrast, reaction of 2-cyano- A3-piperidine 9b (X= CN) with 24 gave the desired C-4 acetylindolesubstituted producta ...