The present invention relates to a process for the alkoxylation of organic compounds comprising the reaction of at least one organic compound with at least one alkoxylating agent in the presence of a catalyst system, wherein a polyether alcohol is obtained. The catalyst system comprises a metallo organic framework mate-rial comprising pores and at least one metal ion and at least one at least bidentate organic compound, which is coordinately bounded to said metal ion. Furthermore it relates to polyurethanes or polyurethane foams, which are obtainable by using a prepared polyether alcohol as a starting material.