24,24 - difluor - vitamin d amp; amp; darr; 3 amp; amp; darr; derivatives, intermediates and processes for their manufacture and their use as drugs

摘要

A novel vitamin D.sub.3 derivative of the formula ##STR1## (wherein R. sub.1 is hydrogen or a hydroxyl group) which exhibits strong biological activity like that of vitamin D and is useful as a medicine; and a process for producing the same are disclosed.