2-Azetidinone
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| Names | |
|---|---|
| IUPAC name
2-Azetidinone | |
| Other names
β-Propiolactam; Azetidin-2-one; 2-Azacyclobutanone | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.156.473 |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| C3H5NO | |
| Molar mass | 71.079 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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2-Azetidinone is a chemical compound with the molecular formula C3H5NO. It is the simplest β-lactam and it forms the central core structure of the β-lactam antibiotics and certain cholesterol medications.[1]
Chemical structure
[edit]The molecular structure of 2-azetidinone features a highly strained four membered ring containing three carbon atoms and a nitrogen atom, with a carbonyl oxygen which is double bonded to the carbon position adjacent to the heteroatom. Because of the significant ring strain inherent to a four-membered geometry, the amide bond within 2-azetidinone is considerably more reactive toward nucleophilic attack than a typical acyclic amide.
Synthesis
[edit]The synthesis of 2-azetidinone is primarily achieved through ring-closure reactions. The Staudinger synthesis, a [2+2] cycloaddition, reacts an imine with a ketene to form the four-membered core.[2] The Gilman-Speeter reaction provides an alternative, using a Reformatsky reagent to achieve cyclization.
Reactivity
[edit]The molecule’s reactivity is driven by its severe ring strain of approximately 26 kcal/mol. This strain prevents the nitrogen lone pair from fully delocalizing into the carbonyl group, rendering the carbonyl carbon highly electrophilic and susceptible to nucleophilic attack.[3]
Medical applications
[edit]The 2-azetidinone ring is the primary pharmacophore in β-lactam antibiotics, including penicillins, cephalosporins, and carbapenems. These compounds function by binding to bacterial transpeptidase enzymes, effectively inhibiting cell wall synthesis.[2] Additionally, the derivative Ezetimibe utilizes the 2-azetidinone scaffold to inhibit intestinal cholesterol absorption.[2]
References
[edit]- ↑ PubChem. "2-Azetidinone". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-05-22.
- 1 2 3 Cordero, F. M.; Giomi, D.; Machetti, F. (2024). "Synthesis of 2-Azetidinones via Cycloaddition Approaches: An Update". Reactions. 5 (3): 492–566. doi:10.3390/reactions5030026.
- ↑ Jarrahpour, A.; Zarei, M. (2007). "Synthesis of Novel N-(4-Ethoxyphenyl) Azetidin-2-ones and Their Oxidative N-Deprotection by Ceric Ammonium Nitrate". Molecules. 12 (10): 2364–2379. doi:10.3390/12102364. PMC 6149079. PMID 17978763.
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