ISOMERIZED VITAMIN D DERIVATIVE

摘要

PROBLEM TO BE SOLVED: To obtain an isomerized vitamin D derivative capable of separating a main effect and a side effect and enlarging a safety zone as a medicine by reversing configuration of hydroxide at 1-position or 3-position, or allowing the 3-position not to bond with hydroxy group. SOLUTION: This isomerized vitamin D derivative is a compound of the formula [R<1> is H or OH; R<2> is a 4-10C organic group (with the proviso that 4-methyl-pentyl and 4-hydroxy-4-methyl-pentyl are omitted); when R<1> is OH, the configuration of the 1-position and the 3-position are (1S,3S), (1R,3R) or (1R,3S)], etc., e.g. (5Z,7E)-26,26,26,27,27,27-hexafluoro-9,10-secocholest-5,7,10(19)- trien-1α,3α,23S,25-tetraol. The objective compound is obtained by protecting all OH in a natural vitamin D derivative of (1S,3R) configuration with t- butyldimethylsilyl group, selectively deprotecting the protecting group at the 3-position with a weak acid, performing oxidation and reduction reactions of the product and thereafter lastly deprotecting the product to provide the objective compound having (1S,3S) configuration at the 1- and 3-positions.