Stereoselective Glycosylations of a Family of 6-Deoxy-1,2-glycals Generated by Catalytic Alkynol Cycloisomerization
作者:Frank E. McDonald、K. Subba Reddy、Yolanda Díaz
DOI:10.1021/ja994229u
日期:2000.5.1
Photolysis of 0.25 equiv of W(CO)6 in the presence of tertiary amines (triethylamine or DABCO) and highly functionalized terminal alkynyl alcohols catalyzes single-step, high-yield cycloisomerization to endocyclic enol ethers. This transformation is general for each diastereomeric 3,4-bissilyl ether of 5-hydroxy-1-hexyne, leading to enantio- and diastereoselective syntheses of each isomer of 6-deoxy-1
在叔胺(三乙胺或 DABCO)和高度官能化的末端炔醇存在下,0.25 当量的 W(CO)6 的光解催化单步、高产率环异构化为内环烯醇醚。这种转化对于 5-羟基-1-己炔的每个非对映异构 3,4-双甲硅烷基醚是通用的,导致 6-脱氧-1,2-乙二醇的每个异构体的对映选择性和非对映选择性合成。每种糖基非对映异构体的立体选择性糖基化也已得到证明,并已应用于 d-洋地黄毒苷-β-4-d-洋地黄糖苷的制备。