Vitamin D-derivater

摘要

The object of the present invention is to provide vitamin D derivatives that have excellent physiological activities as medicines, particularly as therapeutic agents for skin diseases such as psoriasis, and that have a reduced hypercalcemic effect. The present invention provides a vitamin D derivative of Formula (1): wherein X represents an oxygen atom or a sulfur atom; m represents a number of 1 to 3; R1 and R2 each represent a hydrogen atom or an alkyl group; R4 and R5 each represent a hydrogen atom or a hydroxyl group, etc.; R3 represents -YR8, etc.; R6 represents a hydrogen atom, etc.; and R7 represents a hydrogen atom, etc.