Abstract Treatment with a base of hydroxymoyl chlorides derived from sugars led to the corresponding unstable nitrile oxides which, in the absence of nucleophilic or dipolarophilic reagents, dimerize into furoxans. When nitrile oxides are formed in the presence of an excess of acetylenic (or olefinic) dipolarophilic reagents, they give 1,3-dipolar cycloaddition reactions with the formation of the corresponding
摘要用衍生自糖的羟酰
氯进行碱处理会导致相应的不稳定的腈氧化物,在缺乏亲核试剂或双亲亲试剂的情况下,它们会二聚为
呋喃喃。当在过量的炔属(或烯属)双亲亲试剂存在下形成腈氧化物时,它们会进行1,3-偶极环加成反应,并形成相应的3-糖基
异恶唑(或-2-
异恶唑啉)。亲核试剂(例如碱性
氰化物或
乙基溴化镁)的作用分别使糖链延长一个或两个碳原子。
乙炔基溴化镁对这些腈氧化物的作用产生了两种化合物的混合物:α-
乙炔基
肟和3-糖基
异恶唑;