selenoacetal intermediate () was prepared by functional group modification of the side chain in 1α-hydroxyvitamin D2 derivatives. Alkylation with isoamyl bromide gave two diastereoisomers whose configurations were deduced by 13C n.m.r. spectoscopy. A photo-induced deselenation reaction was adopted in order to generate the D3 side chain to the title compound.
通过在1α-羟基
维生素D 2衍
生物中对侧链进行官能团修饰,制备了一种多功能的
硒缩醛中间体()。用异戊基
溴烷基化得到两种非对映异构体,其构型通过13 C nmr光谱法推导。为了产生标题化合物的D 3侧链,采用了光诱导的
脱硒反应。