A process can be used for the preparation of a compound with at least one five-membered cyclic monothiocarbonate group. The process involves a) using a compound with at least one epoxy group as starting material; b) reacting the compound with phosgene or an alkyl chloroformate, thus giving an adduct; and c) reacting the adduct with a compound containing anionic sulfur, thus obtaining the compound with at least one five-membered cyclic monothiocarbonate group.