https://doi.org/10.1351/goldbook.08978
Anionic polymerization in which a cyclic monomer yields a monomeric unit that is either acyclic or contains fewer rings than the cyclic monomer.
Examples: Intramolecular anhydrides of N-carboxy amino acids (commonly referred to as N-carboxy anhydrides or NCAs), epoxides and cyclic siloxanes.