Vitamin D analogues

Abstract

Compounds of the general formula ##STR1## wherein R represents a hydrogen atom or a hydroxyl protecting group, Y represents a hydrogen atom or an optionally protected hydroxyl group, X represents the residue of a dienophile and either R.sup.1 represents a halogen atom a hydrocarbylsulphonyloxy group or a group of the formula --Z--R.sup.3 (in which Z represents --O--, --S--, --SO--, --NR.sup.4 -- or --CR.sup.4 R.sup.5 -- and R.sup.3, R.sup.4 and R.sup.5, which may be the same or different, each represent a hydrogen atom or a straight or branched aliphatic group having 1-12 carbon atoms and which may optionally carry one or more substituents) and R.sup.2 represents a hydrogen atom or R.sup.1 and R.sup.2 together represent an oxo group or an optionally substituted alkylidene group, except that R.sup.1 and R.sup.2 together with the group --CH(CH.sub.3)CH-- to which they are attached do not represent a group having the branched 17.beta.-hydrocarbyl side chain skeleton of vitamin D.sub.2 or vitamin D.sub.3 or use in the preparation of novel vitamin D analogues.

Dependencies are inferred from the claim text.