Abstract: The present invention is concerned with 11-aryloestrane and 11-arylpregnane derivatives, characterized in that these derivatives have the following structure: ##STR1## wherein R.sub.1 is an aryl group with an ##STR2## group as substituent,X and Y each being separately H or a (1-4 C) hydrocarbon radical or together a (2-6 C) hydrocarbon radical;R.sub.2 is an alkyl group containing 1-4 carbon atoms;R.sub.3 is H, OH, a saturated or unsaturated hydrocarbon radical containing 1-8 carbon atoms, at least provided with a hydroxyl, oxo, halogen, azido or nitrile group; an acyloxy or an alkoxy group;R.sub.4 is a hydroxyl, an acyloxy or an alkoxy group or an acyl group optionally provided with a hydroxyl, alkoxy, acyloxy or halogen group; or R.sub.3 and R.sub.4 together form a ring system; andR.sub.5 is a hydrocarbon group containing 1-4 carbon atoms, and further with processes for the preparation of these compounds and with pharmaceutical preparations comprising these compounds.

Abstract: A novel class of steroids having pregnancy-terminating and/or pregnancy-preventing activity and a very low antiglucocorticoid activity have been found. The compounds have the general formula: ##STR1## wherein R.sub.1 and R.sub.2 each separately represent H or a (1-4 C) hydrocarbon radical or together represent a (2-6 C) hydrocarbon radical, R.sub.3 represents H or a (1-4 C) hydrocarbon radical, optionally having an OH substituent, R.sub.4 represents OH or an ester or ether group, or together with R.sub.3 represents O or a heterocyclic ring system containing O, and wherein the broken line indicates an optionally present double bond between the carbon atoms at positions 9 and 10 of the steroid skeleton.