Cytotoxic and Antioxidant Activity of a Series of 4-Methylene-1,3-Dioxolane Acetals

2-Methyl-2-phenoxy-1,4-dioxaspiro[4.4]nonane was synthesized under acid catalysis conditions. The cytotoxic activity of a series of 4-methylene-1,3-dioxolane alkoxy derivatives was studied in vitro against cell lines of human colon cancer HTC-116, human liver cancer HepG2, human lung cancer A549, and human breast cancer MCF-7. The synthesized compounds did not exhibit cytotoxic activity against the studied cell lines and did not increase proliferation of the tumor cells. The antioxidant properties of the acetals were analyzed using an in vitro oxidative stress model. Compounds 14 and 15 were shown to be capable to a certain extent of nullifying the negative effects of reactive oxygen species.