21-norvitamin D compounds

摘要

21-norvitamin D3 analogs in which the methyl group normally attached to the side chain at carbon 20 has been replaced by a hydrogen atom. The compounds are characterized by a marked intestinal calcium transport activity while exhibiting much lower activity than 1 alpha ,25-dihydroxyvitamin D3 in their ability to mobilize calcium from bone. Because of their preferential calcemic activity, these compounds are useful for the treatment of diseases where bone formation is desired, such as osteodystrophy. Novel intermediates formed during the synthesis of the end products are also disclosed.