Azetidine is a saturated heterocyclic organic compound containing three carbon atoms and one nitrogen atom. It is a liquid at room temperature with a strong odor of ammonia and is strongly basic compared to most secondary amines.
Synthesis and occurrence
Azetidines can be prepared by reduction of azetidinones (β-lactams) with lithium aluminium hydride. Even more effective is a mixture of lithium aluminium hydride and aluminium trichloride, a source of "AlClH2" and "AlCl2H".
Azetidine can also be produced by a multistep route from 1,3-disubstituted alkanes. Thus, for example, a multistep route builds azetidine from 3-amino-1-propanol, acrylic acid, thionyl chloride, and base; likewise, azetidine dicarboxylic acids form when glutaric anhydride is brominated (at the α position) and then aminated.
Regio- and diastereoselective synthesis of 2-arylazetidines could be performed from appropriately substituted oxiranes via ring transformation. It is controlled by Baldwin's Rules with remarkable functional group tolerance.
The Paternò−Büchi reaction has an aza analogue.
Azetidine and its derivatives are relatively rare structural motifs in natural products. They are a component of mugineic acids and penaresidins. Perhaps the most abundant azetidine containing natural product is azetidine-2-carboxylic acid - a toxic mimic of proline.
See also Azete, the unsaturated analog
References
External links ChemSynthesis