| abstract |
A vitamin D₃ derivative represented by the following formula:n n wherein, R is, independently, a hydrogen atom, tri(C₁ to C₇ hydrocarbon)silyl group, C₂ to C₈ acyl group, or group forming an acetal bond together with an oxygen atom of a hydroxyl group, A isn n where, R¹ is a methyl group or methylene group, and when R¹ is a methylene group, the bond between the R¹ and the 3-position of the lactone ring is a double bond, R² is a hydrogen atom or C₁ to C₃ alkyl group, R³ is a hydrogen atom, or R² and R³ together indicate a substitutable single methylene group. |