
1,5-Dimethyl-1,2;5,6-diepoxycyclooctane is prepared by epoxidizing 1,5-dimethylcycloocta-1,5-diene with aqueous peracetic or perpropionic acid at a temperature not exceeding 50.degree. C. and within a pH range from 1.5 to 5.5. The diepoxide according to the invention can be cured by means of curing agents for epoxide resins to give moulded materials having valuable mechanical properties. It is also suitable for use as a reactive, latent diluent.











