α,β-unsaturated derivatives of 2-methoxy-2H-3,4-dihydropyran were synthesized. Stereochemical considerations of these heterocycles are briefly discussed. These compounds undergo a rapid first order reaction with water to produce glutaraldehyde, a potent microbial sterilant. Copolymers derived from these compounds and HEMA were found to provide excellent ex amples of clear, hard-sanitizing films; presumably by reaction with at mospheric moisture. Microbiological assays indicate that the release rates of the active agent from the polymers vary greatly depending on the hydrophilic ity of the comonomers.