Enantiomerically substantially pure compounds of the formula ##STR1## where R is H or lower alkyl of 1 to 6 carbons, or pharmaceutically acceptable salts thereof have retinoid-like biological activity. The enantimerically pure or substantially pure compound of the above formula where R is H, or a pharmaceutically acceptable salt thereof, is highly specific agonist of RXR retinoid receptors in preference over RAR receptors.