Compounds of formula IA or IB are provided where X.sub.1, X.sub.2 and X.sub.3 are independently selected from H or hydroxy protecting groups and R.sub.1 is selected from straight or branched chain alkyl groups having from 1 to 8 carbon atoms; straight or branched chain alkenyl groups having from 2 to 8 carbon atoms; straight or branched chain hydroxy-substituted alkyl groups having from 1 to 8 carbon atoms; straight and branched chain hydroxy-substituted alkenyl groups having from 2 to 8 carbon atoms. Such compounds are used in preparing pharmaceutical compositions and are useful in treating a variety of biological conditions. ##STR00001##