以 VD2 为原料制备了 1α,2 5 -二羟基维生素 D3的重要中间体 ( 1 S,6R) -1 -羟基 -6-( 1 ,3-苯并二硫 -2 -氧 ) -3,5 -环维生素 D2 。其中 BDT( 1 ,3-苯并二硫 -2 -氧 )基团的引入有利于共轭三烯系统的保护 The important intermediate of 1α, 25 - dihydroxyvitamin D3 (1 S, 6R) -1 - hydroxy - 6- (1,3 - benzodisulfide - 2 - - Ring vitamin D2. Among them, the introduction of BDT (1,3-benzodithio-2-oxo) group is beneficial to the protection of the conjugated triene system