Caprolactone

Chembox new
Name = Caprolactone
ImageFile = Caprolactone.png ImageSize = 100px
ImageName =
IUPACName = 2-oxepanone
OtherNames = ε-caprolactone
epsilon-caprolactone
6-hexanolactone
Section1 = Chembox Identifiers
CASNo = 502-44-3
SMILES = O=C1OCCCCC1
Section2 = Chembox Properties
Formula = C₆H₁₀O₂
MolarMass = 114.14 g/mol
Density = 1.030 g/cm³
MeltingPt = -1 °C
BoilingPt = 253 °C

Caprolactone is a cyclic ester, known as a lactone, with a ring size of seven. It is a clear colorless liquid that is miscible with most organic solvents except aliphatic hydrocarbons. It reacts slowly with water to form 6-hydroxyhexanoic acid.

Caprolactone is prepared industrially by Baeyer-Villiger oxidation of cyclohexanone with peracetic acid.

The lactone ring is easily opened with nucleophiles including alcohols and water. Caprolactone is a monomer used in the manufacture of various polymers including polycaprolactone. It is also used in synthetic fibers, polyurethane elastomers, plastics, adhesive fabrics, and coatings.

There are three manufacturers in the world, BASF in the USA, Daicel in Japan and the largest Solvay in the UK. Solvay announced in October 2007 that its production unit has been acquired by Perstorp AB of Sweden.

Caprolactone is known to cause severe eye irritation. Exposure may result in corneal injury.

References