Use of the “Zip” Reaction for the Synthesis of a 53‐Membered Polyaminolactam

The general nature of the “zip” reaction has been demonstrated by the synthesis of the decaazalactam (1) with 53 ring members. The immediate precursor, a 13-membered lactam bearing a [(CH2)3NH]9(CH2)3NH2 group at the nitrogen was obtained by the fragment-condensation method. Studies on model compounds show the ring expansion from 13 to 53 members to proceed stepwise as a “zip” reaction.