Readilyavailable 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl chloride smoothly reacts with various silyl enol ethers and silver(I) trifluoromethanesulphonate (triflate) to afford D-C-glucopyranosyl derivatives of α-configuration in high yields, whereas reaction with an electron-rich aromatic nucleophile yields the corresponding β-anomer.
容易获得的2,3,4,6-四ö苄基α- d吡喃葡糖氯化物顺利与各种甲硅烷基烯醇醚和银(反应我)三氟甲磺酸(三氟甲磺酸酯),得到d - C ^ α构型的吡喃葡萄糖基衍生物与高电子芳族亲核试剂反应可得到相应的β-异头物。
The first direct method for C-glucopyranosyl derivatization of 2,3,4,6-tetra-O-benzyl-D-glucopyranose
Commercially available 2,3,4,6-tetra-O-benzyl-D-glucopyranose, activated by trifluoroacetic anhydride reacts, in the presence of Lewis acids, with various silyl enol ethers or with allylsilane to yield C-D-glucopyranosyl derivatives of the α-configuration, and with activated aromatic nucleophiles to yield the corresponding β-anomers.