Abstract: This invention provides a novel class of vitamin D compounds, namely, 13-ethyl and 13-vinyl-18,19-dinor-vitamin D derivatives, as well as a general method for their chemical synthesis. The compounds have the formula: where Y1 and Y2, which may be the same or different, are each selected from the group consisting of hydrogen and a hydroxy-protecting group, R6 is selected from the group consisting of an ethyl or vinyl radical, and where the group R represents any of the typical side chains known for vitamin D type compounds. These 18-substituted compounds are characterized by minimal intestinal calcium transport activity and minimal bone calcium mobilization activity resulting in novel therapeutic agents for the treatment of secondary hyperparathyroidism.

Abstract: This invention provides a novel class of vitamin D compounds, namely, 13-ethyl and 13-vinyl-18,19-dinor-vitamin D derivatives, as well as a general method for their chemical synthesis.

Abstract: This invention provides a novel class of vitamin D compounds, namely, 13-ethyl and 13-vinyl-18,19-dinor-vitamin D derivatives, as well as a general method for their chemical synthesis. The compounds have the formula: where Y1 and Y2, which may be the same or different, are each selected from the group consisting of hydrogen and a hydroxy-protecting group, R6 is selected from the group consisting of an ethyl or vinyl radical, and where the group R represents any of the typical side chains known for vitamin D type compounds. These 18-substituted compounds are characterized by minimal intestinal calcium transport activity and minimal bone calcium mobilization activity resulting in novel therapeutic agents for the treatment of secondary hyperparathyroidism.

Abstract: A method of treating metabolic bone diseases such as osteoporosis, as well as other disease states treatable with vitamin D compounds, comprises administering an effective amount of one or more modified vitamin D compound. The modified compound contains a typical vitamin D nucleus but with in vivo hydrolyzable groups at one or more of the 1, 3 and 25 carbon positions. The time of conversion of the modified compound to its active form, such as calcitriol, can be regulated to thus provide controlled release of the compound in vivo over time, by changing or modifying the hydrolyzable groups.

Abstract: This invention provides a novel class of vitamin D compounds, namely, 13-ethyl and 13-vinyl-18,19-dinor-vitamin D derivatives, as well as a general method for their chemical synthesis. The compounds have the formula: ##STR1## where Y.sub.1 and Y.sub.2, which may be the same or different, are each selected from the group consisting of hydrogen and a hydroxy-protecting group, R.sub.6 is selected from the group consisting of an ethyl or vinyl radical, and where the group R represents any of the typical side chains known for vitamin D type compounds. These 18-substituted compounds are characterized by minimal intestinal calcium transport activity and minimal bone calcium mobilization activity resulting in novel therapeutic agents for the treatment of secondary hyperparathyroidism.