The biological activity of cyclic acetals (penta- and dipentaerythritol, ethriol, and diglycerol) and 5-ethyl-5-hydroxymethyl-1,3-dioxane esters was studied in vitro. The cytotoxic properties of 5-ethyl-5-hydroxymethyl-1,3-dioxane esters were established on HEK293 and SH-SY5Y cell lines. Potential antioxidant properties of 7,11,18,21-tetraoxaspiro-5,2,2,5-heneicosane, 2-[(5-ethyl-5-hydroxymethyl)-1,3-dioxan-2-yl]phenol, 4.4-[oxydi(methylene)]-bis-2-diisopropyl-1,3-dioxolane, 4,4_-[oxydi(methylene)]-bis-1,3-dioxolane, (5-ethyl-1,3-dioxan-5-yl)methyl-2-methyl acrylate, and bis(5-ethyl-1,3-dioxan-5-yl)methyl maleate were established in vitro using an oxidative stress model.