The invention relates to 17-hydroxy-19-nor-21-carboxylic acid-steroid γ-lactone derivatives with the chemical formula I, where R4, R6a, R6b, R7, R15, R16a, R16b, R18 and Z have the meanings stated in claim 1, and their solvates, hydrates, stereoisomers and salts. The invention further relates to the use of these derivatives for the production of a medicinal product for oral contraception and for the treatment of pre-, peri- and postmenopausal complaints and medicinal products that contain said derivatives. The derivatives according to the invention have a progestational and in preferred cases additionally an antimineralocorticoid and neutral to slightly androgenic action.