Cyclic Ethers Heterocyclic:oxygen is in ring. .Epoxides (oxiranes) ·Oxetanes 9 ·Furans (Oxolanes ·Pyrans 〔）(Oxanes .Dioxanes => Chapter 14 10Chapter 14 10 Cyclic Ethers • Heterocyclic: oxygen is in ring. • Epoxides (oxiranes) H2C CH2 O • Oxetanes O • Furans (Oxolanes ) O O • Pyrans (Oxanes ) O O •Dioxanes O O =>