作者:Carla Marino、Oscar Varela、Rosa M. de Lederkremer
DOI:10.1016/0008-6215(89)84147-3
日期:1989.7
disaccharide derivative having both units in the furanoid form. Thus, diisoamylborane reduction of the lactone function of 6 led to the disaccharide derivative 10, from which the methyl glycoside 12 was prepared. O-Debenzoylation of 12 gave the corresponding methyl beta-D-galactofuranosyl-(1----6)-beta-D-galactofuranoside. The free disaccharide beta-D-Galf-(1----6)-D-Galp and its acetylated derivative were
通过氯化锡(IV)催化五-O-苯甲酰基-α,β-D-半乳糖呋喃糖的糖基化,然后用甲醇钠进行脱苯甲酰化,可以轻松获得甲基β-D-半乳糖呋喃糖苷。将1,与2,3,5-三-O-苯甲酰基-D-半乳糖基-1,4-内酯或与6-O-三苯甲基-内酯衍生物5进行糖基化,得到苯甲酰化的β-D-D-半呋喃糖基-(1- --6)-D-半乳糖-1,4-内酯6,收率极高。通过硼氢化物还原成糖基-糖醇7证实了二糖6的结构。1与4或5的缩合反应的副产物被鉴定为苯甲酰化的(1-1)-β,β'-D-半乳糖呋喃糖基二糖8。在氯化锡的存在下,通过向1中加水可容易地制备化合物8(收率88%)。8的O-脱苯甲酰化得到结晶的β' -D-半呋喃糖基-(1 ---- 1)-β-D-半呋喃糖苷 糖基内酯6构成用于合成具有两个呋喃形式的二糖衍生物的关键中间体。因此,内酯官能团的二异戊基硼烷还原导致二糖衍生物10,由此制备了甲基糖苷12。12的