Acetal‐Based Functional Epoxide Monomers: Polymerizations and Applications

Protecting group chemistry is essential for various organic transformation and polymerization processes. In particular, conventional anionic ring‐opening polymerization (AROP) often requires proper protecting group chemistry because it is typically incompatible with most functional groups due to the highly basic and nucleophilic conditions. In this context, many functional epoxide monomers with proper protecting groups are developed, including the acetal group as a representative example. Since the early introduction of ethoxyethyl glycidyl ether, there is significant development of acetal‐based monomers in the polyethers. These monomers are now utilized not only as protecting groups for hydroxyl groups under AROP conditions but also as pH‐responsive moieties for biomedical applications, further expanding their utility in the use of functionalized polyethers. Recent progress in this field is outlined from their synthesis, polymerization, and biomedical applications. While protecting‐group chemistry is essential in anionic ring‐opening polymerization, recent development in the acetal‐based epoxide monomers is utilized as not only protecting groups but also pH‐responsive moieties for biomedical applications. The recent progress of the acetal‐based functional epoxide monomers is outlined from the synthesis and polymerization to their applications.