VITAMIN D DERIVATIVES

摘要

The object of the present invention is to provide a vitamin D derivative exhibiting excellent physiological activity as medicines, in particular as therapeutic agents for skin disease including psoriasis, and having decreased hypercalcemic activity. The present invention provides vitamin D derivatives represented by the general Formula (1): wherein in Formula (1), X is oxygen or sulfur; R1 is hydrogen or Formula (2) R2 is hydrogen or alkyl; R3 and R4 are hydrogen or alkyl or R3 and R4 together form a double bond between the 16- and 17-positions; R5 is hydrogen or -OR13 in which R13 is hydrogen or a protecting group; and R6 is hydrogen or a protecting group.it