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
):
1
wherein
in Formula (
1
), X is oxygen or sulfur;
R
1
is hydrogen or Formula (
2
)
2
R
2
is hydrogen or alkyl;
R
3
and R
4
are hydrogen or alkyl or R
3
and R
4
together form a double bond between the
16
- and
17
-positions;
R
5
is hydrogen or -OR
13
in which R
13
is hydrogen or a protecting group; and
R
6
is hydrogen or a protecting group.