Synthesis of Monocyclic Rings with One Heteroatom

For all the saturated monocycles with one heteroatom, intramolecular nucleophilic displacement with the formation of C-Z bond(s) is an important preparative method (Section 4.2.1.2.). 

Further significant synthetic routes for the various ring sizes are  

1 From Acyclic Compounds by Concerted Formation of Two Bonds 

Electron-deficient C = C double bonds are resistant to electrophilic attack, but are converted into oxiranes by nucleophilic oxidants such as H02 . 

Electrophilic nitrogen compounds, such as arenesulfonyloxyamines, can convert alkenes to aziridines without the intervention of free nitrenes (80CC560). The ylide Ph2S+-NH adds stereospecifically to E and Z conjugated alkenes, and chiral sulfimides can transfer chirality to the aziridines formed (80T73). These reactions are often named aziridinations . 

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