PROCESS FOR THE PREPARATION OF DIOL

The invention provides a process for producing diol, characterized in that the process comprises the steps of (1-i) addition of alkylene oxide and carbon dioxide to an H-functional starter substance in the presence of a catalyst to obtain polyether carbonate polyol and cyclic carbonate, (1-ii) separation of the cyclic carbonate from the resulting reaction mixture from step (1-i), (1-iii) hydrolytic cleavage of the cyclic carbonate separated from step (1-ii) into carbon dioxide and diol, (1-iv) optionally distillative purification of the diol from step (1-iii), wherein (η) to the cyclic carbonate from step (1-ii) and/or to the diol a Lewis or Brønsted acid, excluding carboxylic acids having a pKa of >3.0, and optionally water are added and the reaction mixture obtained is optionally neutralized.