Oligosaccharide Analogues of Polysaccharides. Part 9. Synthesis and Thermolysis of Acetylenosaccharide-Derived 1,2-Dialkynylbenzenes
作者:Jinwang Xu、Anita Egger、Bruno Bernet、Andrea Vasella
DOI:10.1002/hlca.19960790722
日期:1996.10.30
independently of the presence or absence of 1,4-cyclohexadiene; 23 was formed from 22 (Scheme 2). Acetolysis of 22 gave the hexaacetate 24 that was completely debenzylated by thiolysis, yielding the diol 26 and trans-stilbene, evidencing the nature and position of the bridge between the glucosyl moieties (Scheme 3). Thiolysis of 22 yielded the unprotected 2,3-diglucosylnaphthalene 28, a new type of C-glycosides
研究了1,2-双(葡萄糖基炔基)苯6和16的热解作用,以评估分子内H键对Bergman-Masamune-Sondheimer环芳烃化活化能的影响,并评估了环芳烃化用于合成的用途二糖基化萘。所述dialkynes通过交叉耦合的制备Ò -benzylated或ö -silylated glucosylalkynes 1和4(方案1)。硫解已知的1,或乙酰解1,接着脱乙酰(23)和甲硅烷基化,得到4。1或4与碘或1,2-二碘联苯的交叉偶联取决于所加胺的性质和保护基团,并导致生成单和二炔基苯5和6或12,13和15,分别。苯甲醚5和6在BF 3 ·OEt 2催化下乙酰水解时收率较差,而Ac 2 O / CoCl 2 ·6 H 2 O以良好的收率将6转化为区域选择性脱苄基的10。甲硅烷基化7和13分别给出了醇8和14。热分解6在PhCl,得到22和23,独立地存在或不存在的1,4-环己二烯的; 2