Three-Membered Ring Heterocycles

Abstract In this chapter the chemistry and structural aspects of three-membered saturated and unsaturated nitrogen, oxygen, and sulfur heterocycles with monoheteroatoms such as aziridine, 1 H -azirine, 2 H -azirine, oxirane, oxirene, thiirane, thiirane-1,1-dioxide, thiirene, thiirene-1-oxide, and thirene-1,1-dioxide are described. Analogously the structural aspect and chemistry of saturated and unsaturated heterocycles with two similar heteroatoms such as diaziridine, diazirine, dioxirane, dithiirane, and with mixed heteroatoms such as oxaziridine, oxathiirane, and thiazirine are also delineated. The importance of these heterocycles in natural products, medicine, and material science has been introduced.