Studies of vitamin D (calciferol) and its analogs. 41. 18-Substituted derivatives of vitamin D: 18-acetoxy-1.alpha.,25-dihydroxyvitamin D3 and related analogs
摘要:
The bridged ether 6, produced via light-induced lead tetraacetate oxidation of Grundmann's alcohol 5, was transformed in three to four steps to the CD-ring ketones 9b and 10 which were then transformed via Homer-Wittig coupling to the 18-acetoxy analogues of vitamin D3, 25-hydroxyvitamin D3, 1-alpha,25-dihydroxyvitamin D3, and 1-alpha-hydroxyvitamin D3 (4a-d, respectively). The biological evaluation of 4a-d in terms of their ability to elicit intestinal calcium absorption and bone calcium mobilization in vivo in the chick is reported. These vitamin D analogues, the first in this steroid series modified at the C-18 position, are nearly devoid of activity. In vitro data for 4a-d in terms of their ability to bind to the chick intestinal receptor as compared to the natural hormone 1-alpha,25-dihydroxyvitamin D3, parallels the in vivo data.
Studies of vitamin D (calciferol) and its analogs. 41. 18-Substituted derivatives of vitamin D: 18-acetoxy-1.alpha.,25-dihydroxyvitamin D3 and related analogs
作者:David F. Maynard、Anthony W. Norman、William H. Okamura
DOI:10.1021/jo00037a046
日期:1992.5
The bridged ether 6, produced via light-induced lead tetraacetate oxidation of Grundmann's alcohol 5, was transformed in three to four steps to the CD-ring ketones 9b and 10 which were then transformed via Homer-Wittig coupling to the 18-acetoxy analogues of vitamin D3, 25-hydroxyvitamin D3, 1-alpha,25-dihydroxyvitamin D3, and 1-alpha-hydroxyvitamin D3 (4a-d, respectively). The biological evaluation of 4a-d in terms of their ability to elicit intestinal calcium absorption and bone calcium mobilization in vivo in the chick is reported. These vitamin D analogues, the first in this steroid series modified at the C-18 position, are nearly devoid of activity. In vitro data for 4a-d in terms of their ability to bind to the chick intestinal receptor as compared to the natural hormone 1-alpha,25-dihydroxyvitamin D3, parallels the in vivo data.