A series of 16-en-22-oxa-derivatives of vitamin D-3 based on the structure of maxacalcitol (2) were prepared. Maxacalcitol is currently used topically for the treatment of psoriasis and is recognized as the most successful antedrug of natural vitamin D-3 because it retains the original antiproliferative activity of calcitriol without increased calcemic activity. We introduced 16-olefinic functionality to accelerate the oxidative metabolism of the drug in liver, presumed to be essential for the reduction of calcemic activity, and modified the side-chain moiety by placing the 22-oxygen on the more labile allylic carbon center. Novel 22-oxa analogs (7a-i), carrying either the 24-alkynyl bond or 24-hydroxy functionality in addition to the 16-double bond were synthesized and their pharmacokinetics were evaluated. (c) 2005 Elsevier Ltd. All rights reserved.
A series of 16-en-22-oxa-derivatives of vitamin D-3 based on the structure of maxacalcitol (2) were prepared. Maxacalcitol is currently used topically for the treatment of psoriasis and is recognized as the most successful antedrug of natural vitamin D-3 because it retains the original antiproliferative activity of calcitriol without increased calcemic activity. We introduced 16-olefinic functionality to accelerate the oxidative metabolism of the drug in liver, presumed to be essential for the reduction of calcemic activity, and modified the side-chain moiety by placing the 22-oxygen on the more labile allylic carbon center. Novel 22-oxa analogs (7a-i), carrying either the 24-alkynyl bond or 24-hydroxy functionality in addition to the 16-double bond were synthesized and their pharmacokinetics were evaluated. (c) 2005 Elsevier Ltd. All rights reserved.
A compound having the formula (4):
wherein
1
X is oxygen or sulfur, R
9
and R
10
are each a hydrogen or a protecting group, and R
11
is an aliphatic hydrocarbon, a —COR
12
group where R
12
is alkyl, aryl or alkoxy, or a group of formula
2
wherein R
5
and R
6
are each hydrogen or hydroxyl, m is 1 to 4, and n is 0-2.
A compound having the formula (4): wherein
X is oxygen or sulfur, R9 and R10 are each a hydrogen or a protecting group, and R11 is an aliphatic hydrocarbon, a —COR12 group where R12 is alkyl, aryl or alkoxy, or a group of formula
wherein R5 and R6 are each hydrogen or hydroxyl, m is 1 to 4, and n is 0-2.