20-position modified pharmaceutically active vitamin D series compounds

摘要

The invention relates to vitamin D derivatives, modified in 20- position, of general formula I ##STR1## in which X, Y, Z, R.sub.1, R.sub. 2 as well as R.sub.3 have the meaning indicated in the description, process for their production and their use as agents for treatment of hyperproliferative diseases of the skin.