These molecules can also be prepared by the ring closure of 1,2-amino alcohols in the presenc of sulphuric acide via the Wenker synthesis, and the high ring strain in these compounds makes them useful for synthetic reactions because they easily undergo ring opening by nucleophilic attack.
An exciting reaction developed by Ishikawa sees aldehydes transformed into these molecules via a guanidium ylide mediated step, and Taguchi developed an "intramolecular trapping" variant of a reaction wherein  these functional groups are formed by treating ketoximes with excess Grignard reagents. Experiments by Laurent et al demonstrated the mechanism of that reaction, which is named for Hoch and Campbell reaction. Quizbowlers may appreciate the fact that taurine can be synthesized by the reaction of the simplest of these compounds with sulphurous acid, and other methods of preparing them include the reaction of carbenes with imines. These molecules can also be prepared by the ring closure of 1,2-amino alcohols in the presenc of sulphuric acide via the Wenker synthesis, and the high ring strain in these compounds makes them useful for synthetic reactions because they easily undergo ring opening by nucleophilic attack. Sometimes called the aza-variats of epoxides, for 10 points, identify these functional groups which are three-membered heterocyclic rings wherein two carbon atoms are bound to a nitrogen atom, which are sometimes known as ethenyl-imines. 
An exciting reaction developed by Ishikawa sees aldehydes transformed into these molecules via a guanidium ylide mediated step, and Taguchi developed an "intramolecular trapping" variant of a reaction wherein  these functional groups are formed by treating ketoximes with excess Grignard reagents.
{aziridines} [accept {ethenylamine} until mentioned; prompt on "{aza variants} of {epoxides}" until mentioned; {grudgingly} accept {aza}-{ethylene}]