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Greek prefixes in alphabetical order indicate ring size:
- α-lactam (3 ring atoms)
- β-lactam (4 ring atoms)
- γ-lactam (5 ring atoms)
- δ-lactam (6 ring atoms)
- ε-lactam (7 ring atoms)
General synthetic methods exist for the organic synthesis of lactams.
- Lactams form by the acid-catalyzed rearrangement of oximes in the Beckmann rearrangement.
- Lactams form from cyclic ketones and hydrazoic acid in the Schmidt reaction.
- Lactams form from cyclisation of amino acids.
- Lactams form from intramolecular attack of linear acyl derivatives from the nucleophilic abstraction reaction.
- In iodolactamization  an iminium ion reacts with an halonium ion formed in situ by reaction of an alkene with iodine.
- Lactams form by copper-catalyzed 1,3-dipolar cycloaddition of alkynes and nitrones in the Kinugasa reaction
- Diels-Alder reaction between cyclopentadiene and chlorosulfonyl isocyanate (CSI) can be utilized to obtain both β- as well as γ-lactam. At lower temp (−78°C), β-lactam is the preferred product. At optimum temperatures, a highly useful γ-lactam known as Vince Lactam is obtained.
Tautomerization to Lactim
- Lactams can polymerize to polyamides.
- β-lactam with a four-membered ring found in beta-lactam antibiotics. Penicillin, considered the most famous antibiotic, is a β-lactam antibiotic.
- Lactone, a cyclic ester.
- Spencer Knapp, Frank S. Gibson Organic Syntheses, Coll. Vol. 9, p.516 (1998); Vol. 70, p.101 (1992) Online article
- Singh, R.; Vince, R. Chem. Rev. 2012, 112 (8), pp 4642–4686."2-Azabicyclo[2.2.1]hept-5-en-3-one: Chemical Profile of a Versatile Synthetic Building Block and its Impact on the Development of Therapeutics"
- Pham, P.-T.; Vince, R. Phosphorus, Sulphur and Silicon 2007, 779-791.