Use of carbon-2-modified-vitamin D analogs to induce the formation of new bone

A method of stimulating growth of new bone in a mammal comprising administering to a mammal in need thereof a therapeutically effective amount of a compound having the formula:

• 12
• where Y1 and Y2, which may be the same or different, are each selected from the group consisting of hydrogen and a hydroxy-protecting group, where R11 and R12 are each hydrogen or taken together are a methylene group, where R6 and R7, which may be the same or different, are each selected from the group consisting of hydrogen, alkyl, hydroxyalkyl, fluoroalkyl, hydroxy and alkoxy, with the proviso that R6 and R7 cannot both be hydrogen, or R6 and R7 when taken together may represent the group —(CH2)x— where X is an integer from 2 to 5, or R6 and R7 when taken together may represent the group ═CR8R9 where R8 and R9, which may be the same or different, are each selected from the group consisting of hydrogen, alkyl, hydroxyalkyl, fluoroalkyl, hydroxy and alkoxy, or when taken together R8 and R9 may represent the group —(CH2)x— where X is an integer from 2 to 5, and where the group R represents
• 13
• where the stereochemical center (corresponding to C-20 in steroid numbering) may have the R or S configuration, (i.e. either the natural configuration about carbon 20 or the 20-epi configuration), and where Z is selected from Y, —OY, —CH2OY, —C≡CY and —CH═CHY, where the double bond may have the cis or trans geometry, and where Y is selected from hydrogen, methyl, —COR5 and a radical of the structure:
• 14
• where m and n, independently, represent the integers from 0 to 5, where R1 is selected from hydrogen, deuterium, hydroxy, protected hydroxy, fluoro, trifluoromethyl, and C1-5-alkyl, which may be straight chain or branched and, optionally, bear a hydroxy or protected-hydroxy substituent, and where each of R2, R3, and R4, independently, is selected from deuterium, deuteroalkyl, hydrogen, fluoro, trifluoromethyl and C1-5 alkyl, which may be straight-chain or branched, and optionally, bear a hydroxy or protected-hydroxy substituent, and where R1 and R2, taken together, represent an oxo group, or an alkylidene group, ═CR2R3, or the group —(CH2)p—, where p is an integer from 2 to 5, and where R3 and R4, taken together, represent an oxo group, or the group —(CH2)q—, where q is an integer from 2 to 5, and where R5 represents hydrogen, hydroxy, protected hydroxy, or C1-5 alkyl and wherein any of the CH-groups at positions 20, 22, or 23 in the side chain may be replaced by a nitrogen atom, or where any of the groups —CH(CH3)—, —(CH2)m—, —CR1R2— or —(CH2)n— at positions 20, 22, and 23, respectively, may be replaced by an oxygen or sulfur atom.