amino sugars with thiophosgene. In the absence of base, all isothiocyanates were stable and could be stored and acetylated without decomposition. In the presence of triethylamine, 6,6'-dideoxy-6,6'-diisothiocyanato-alpha,alpha'-trehalose underwent intramolecular cyclisation involving HO-4 to give the corresponding bis(cyclic thiocarbamate). The product of cyclisation at a single glucopyranosyl unit
6,6'-Dideoxy-6,6'-diisothiocyanato-alpha,alpha'-
海藻糖(4),6-deoxy-6-isothiocyanato-alpha-
D-果糖呋喃糖β-
D-果糖吡喃糖1,2':2 ,1'-二酐(11),6,6'-二
脱氧-6,6'-二异
硫氰酸根合
蔗糖(16)和全(6-
脱氧-6-异
硫氰酸根合)-环
麦芽六糖(23),-环麦芽庚糖(27)和通过使相应的
氨基糖与
硫光气反应以高收率制备β-环麦芽八糖(31)。在没有碱的情况下,所有异
硫氰酸酯都是稳定的,可以储存和乙酰化而不会分解。在
三乙胺的存在下,将涉及HO-4的6,6'-二
脱氧-6,6'-二异
硫氰基-α,α'-
海藻糖进行分子内环化反应,得到相应的双(环状
硫代
氨基甲酸酯)。在上述二异
硫氰酸酯与混合的(H +,HO-)离子交换
树脂的处理中,获得了在单个
吡喃
葡萄糖基单元上的环化产物。在相同的反应条件下,6,6'-二
脱氧-6