AbstractNew monomers containing aldehyde groups in the alcohol component of methacrylates were prepared. The structure of these monomers prevents undesired spontaneous intramolecular cyclization reactions of pendant aldehyde groups of the corresponding polymers. 2,2‐Diethoxyethyl methacrylate(1)and its saturated analog, 2,2‐diethoxyethyl pivalate(3)and 3,3‐diethoxypropyl methacrylate(2)were prepared. The conditions for a selective hydrolysis of the acetal function of these compounds, leading to the corresponding aldehydes, were st