Synthesis of l-iduronic acid derivatives by epimerisation of anancomeric d-glucuronic acid analogues
作者:Neil Baggett、Alan Smithson
DOI:10.1016/s0008-6215(00)81890-x
日期:1982.10
Abstract Derivatives of l -iduronic acid were prepared by epimerisation of d -glucuronic acid derivatives that were constrained to adopt a conformation having C-6 in an axial position, so that the l -iduronic acid derivatives would be thermodynamically more stable. Methyl 3,5- O -benzylidene-1,2- O -isopropylidene-β- l -idofuranuronate was conveniently obtained in 23% yield by crystallisation from
摘要通过对d-葡萄糖醛酸衍生物进行差向异构化,制得了1-iduronic酸的衍生物,这些衍生物必须被限制为采用在轴向位置具有C-6的构象,从而使l-iduronic酸衍生物在热力学上更加稳定。通过从差向异构混合物中结晶,可以方便地以23%的产率获得3,5-O-亚苄基-1,2-O-异亚丙基-β-1-呋喃呋喃甲酸甲酯,并且其特征在于通过还原为相应的醇或通过催化氢化随后进行。通过自发环化得到1,2-O-异亚丙基-β-1-呋喃基呋喃基-6,3-内酯。设计了由d-葡糖呋喃尿酸酯-6,3-内酯分两步合成3,5-O-亚苄基-1,2-O-异亚丙基-α-d-呋喃葡萄糖醛酸甲酯的方法。差向异构的其他候选物,包括其他酯,酰胺和腈,还进行了检查。在所有情况下,通过竞争性分解(可能涉及β消除)都会降低产量。