AbstractA new heterocyclic monomer is developed via simple Diels–Alder reaction which is reluctant to polymerize in dichloromethane (DCM) whereas undergoes facile polymerization in tetrahydrofuran with excellent control over molecular weight (Mn) and dispersities (Đ) using Grubbs' third generation catalyst (G3). The deprotection of the tert‐butoxycarbonyl group from the polymeric backbone yielded a water‐soluble ring opening metathesis polymerization (ROMP) polymer easily. Moreover, in DCM this new monomer copolymerizes with 2,3‐dihydrofuran under catalytic living ROMP conditions to give backbone degradable polymers. All the synthesized polymers are characterized by size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR) spectroscopy. It is believed that this new route to water soluble ROMP homopolymers as well as the cost‐effective and environmentally friendly route to degradable copolymers and block‐copolymers could find applications in biomedicine in the near future.