Vitamin D analogues

Abstract

Compounds of the formula I wherein X represents hydrogen or hydroxy; R1 and R2, which may be the same or different, represent hydrogen, (C1-C4)alkyl optionally substituted with one hydroxyl group or one or more fluorine atoms, or, together with the carbon atom to which they are attached, R1 and R2 form a (C3-C5)carbocyclic ring; R3 represents (C1-C4)alkyl, (C1-C4)alkoxy or a halogen atom, such as fluorine, chlorine, bromine, or iodine, and in-vivo hydrolyzable esters thereof with pharmaceutically acceptable acids, may be used in the prophylaxis and/or treatment of dieases characterized by abnormal cell differentiation and/or cell proliferation.

Dependencies are inferred from the claim text.