Dioxolane is a heterocyclic acetal with the formula (CH2)2O2CH2. It is related to tetrahydrofuran by exchanging an oxygen for the CH2 group. The isomer 1,2-dioxolane (in which the two oxygen centers are adjacent) is a peroxide. 1,3-Dioxolane is used as solvent and comonomer in polyacetal. The dioxolane-type and their hydrogenolysis can provide very valuable partially protected building blocks either for oligosaccharide syntheses or sugar transformations.
Oxirane is a three-membered ring compound consisting of one oxygen atom and two carbon atoms. Oxirane is present in natural products such as cryptocin, which has anticancer properties, and azidomycin, trienone, and epoxidomycin, which have shown activity against drug-resistant leukemias and AIDS-related lymphomas. Other oxirane containing bioactive molecules have anti-inflammatory, immunosuppressive, and antitumor activities. Oxiranes are a strained ring susceptible to various nucleophilic, ring-opening or rearrangement reactions, so they are considered to be one of the most important intermediates in organic synthesis.