Caprolactone
ε-Caprolactone
Hexano-6-lactone
6-Hexanolactone
Hexan-6-olide
1-Oxa-2-oxocycloheptane
- 502-44-3 checkY
- CHEBI:17915 checkY
- ChEMBL373123 checkY
- 9972 checkY
- C01880 checkY
- 56RE988L1R checkY
- InChI=1S/C6H10O2/c7-6-4-2-1-3-5-8-6/h1-5H2 checkYKey: PAPBSGBWRJIAAV-UHFFFAOYSA-N checkY
- InChI=1/C6H10O2/c7-6-4-2-1-3-5-8-6/h1-5H2Key: PAPBSGBWRJIAAV-UHFFFAOYAG
- C1CCC(=O)OCC1
ε-Caprolactone or simply caprolactone is a lactone (a cyclic ester) possessing a seven-membered ring. Its name is derived from caproic acid. This colorless liquid is miscible with most organic solvents and water. It was once produced on a large scale as a precursor to caprolactam.[3]
Production and uses
[edit ]Caprolactone is prepared industrially by Baeyer-Villiger oxidation of cyclohexanone with peracetic acid.
Caprolactone is a monomer used in the production of highly specialised polymers. Ring-opening polymerization, for example, gives polycaprolactone.[3] Another polymer is polyglecaprone, used as suture material in surgery.[4]
Reactions
[edit ]Although no longer economical, caprolactone was once produced as a precursor to caprolactam. Caprolactone is treated with ammonia at elevated temperatures to give the lactam:
- (CH2)5CO2 + NH3 → (CH2)5C(O)NH + H2O
Carbonylation of caprolactone gives, after hydrolysis, pimelic acid. The lactone ring is easily opened with nucleophiles including alcohols and water to give polylactones and eventually the 6-hydroxyadipic acid.
Related compounds
[edit ]Several other caprolactones are known, including α-, β-, γ-, and δ-caprolactones. All are chiral. (R)-γ-caprolactone is a component of floral scents and of the aromas of some fruits and vegetables,[5] and is also produced by the Khapra beetle as a pheromone.[6] δ-caprolactone is found in heated milk fat.[7]
An ether of caprolactone is used as a binder for AP/AN/Al rocket propellant HTCE: Hydroxy-Terminated Caprolactone Ether [8]
Safety
[edit ]Caprolactone hydrolyses rapidly and the resulting hydroxycarboxylic acid displays unexceptional toxicity, as is common for the other hydroxycarboxylic acids.[9] It is known to cause severe eye irritation. Exposure may result in corneal injury.[1]
References
[edit ]- ^ a b "ε-caprolactone SIDS Initial Assessment Report" (PDF). OECD. Archived from the original (PDF) on 2011年08月15日. Retrieved 2017年10月12日.
- ^ "Capa Monomer product data sheet" (PDF). Perstorp. 2015年02月27日. Archived from the original (PDF) on 2017年02月02日. Retrieved 2017年10月11日.
- ^ a b Köpnick, Horst; Schmidt, Manfred; Brügging, Wilhelm; Rüter, Jörn; Kaminsky, Walter (2002). "Polyesters". Ullmann's Encyclopedia of Industrial Chemistry (6th ed.). Weinheim: Wiley-VCH. doi:10.1002/14356007.a21_227.
- ^ "glycolide E-caprolactone copolymer Summary Report". CureHunter. Retrieved 2017年10月11日.
- ^ Mosandl, A.; Günther, C. (1989). "Stereoisomeric flavor compounds: structure and properties of γ-lactone enantiomers". Journal of Agricultural and Food Chemistry. 37: 413–418. doi:10.1021/jf00086a031.
- ^ Nunez, M. Teresa; Martin, Victor S. (1990). "Efficient oxidation of phenyl groups to carboxylic acids with ruthenium tetraoxide. A simple synthesis of (R)-γ-caprolactone, the pheromone of Trogoderma granarium". Journal of Organic Chemistry. 55 (6): 1928–1932. doi:10.1021/jo00293a044.
- ^ Parliament, Thomas H.; Nawar, Wassef W.; Fagerson, Irving S. (1965). "Delta-Caprolactone in Heated Milk Fat". Journal of Dairy Science. 48 (5): 615–616. doi:10.3168/jds.S0022-0302(65)88298-4 .
- ^ HTCE
- ^ Miltenberger, Karlheinz (2002). "Hydroxycarboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry (6th ed.). Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_507.