Synthesis of non-glycosidic 4,6′-thioether-linked disaccharides as hydrolytically stable glycomimetics
作者:María Laura Uhrig、László Szilágyi、Katalin E. Kövér、Oscar Varela
DOI:10.1016/j.carres.2007.03.025
日期:2007.9
of the protecting groups of 8 by acid hydrolysis, formation of an 1,6-anhydro bridge was observed in the 3-deoxy-4-thiohexopyranose unit (10). The free non-glycosidic thioether-linked disaccharide 3-deoxy-4-S-(6-deoxy-alpha,beta-D-galactopyranos-6-yl)-4-thio-alpha,beta-D-xylo-h exopyranose (11) was obtained by acetolysis of 10 followed by O-deacetylation. A similar sequence starting from the enone
将1,2:3,4-二-O-异亚丙基-6-硫代-α-D-半乳糖(2)迈克尔加成至2-丙基6-O-乙酰基-3,4-二脱氧-α-D-甘油-hex-3-enopyranosid-2-ulose(1)作为主要的非对映异构体,提供了2-丙基6-O-乙酰基-3-脱氧-4-S-(6-脱氧-1,2:3,4-二-O-异亚丙基-α-D-吡喃并吡喃半乳糖s-6-基)-4-硫代α-D-苏-吡喃并吡喃糖苷-2-果糖(3,产率91%)。还原3的羰基,然后进行O-脱乙酰基处理,以1:2的比例得到两个差向异构体7(α-D-lyxo)和8(α-D-xylo)。通过酸水解除去8的保护基时,在3-脱氧-4-硫代己吡喃糖单元(10)中观察到1,6-脱水桥的形成。游离的非糖苷硫醚连接的二糖3-deoxy-4-S-(6-deoxy-alpha,beta-D-galactopyranos-6-yl)-4-thio-alpha,β-D-x