Synthesis of C-mannopyranosylphloroacetophenone derivatives and their anomerization
作者:Toshihiro Kumazawa、Shingo Sato、Shigeru Matsuba、Jun-ichi Onodera
DOI:10.1016/s0008-6215(01)00076-3
日期:2001.5
The reaction of 2,3,4-tri-O-benzyl-alpha-L-rhamnopyranosyl fluoride (6-deoxy-2,3,4-tri-O-benzyl-alpha-L-mannopyranosyl fluoride) with 2,4-dibenzylphloroacetophenone, in the presence of boron trifluoride.diethyl etherate, afforded both the 3-C-alpha-L- and the 3-C-beta-L-rhamnopyranosylphloroacetophenone derivatives. The 3-C-alpha-L-rhamnoside was produced as a major product, while the 3-C-beta-L-rhamnoside
2,3,4-三-O-苄基-α-L-鼠李吡喃糖基氟(6-脱氧-2,3,4-三-O-苄基-α-L-甘露吡喃糖基氟)与2,4-的反应在三氟化硼·二乙基醚化物的存在下,二苄基苯乙酰苯乙酮提供了3-C-α-L-和3-C-β-L-鼠李糖基吡喃糖基苯乙酮衍生物。3-C-α-L-鼠李糖苷是主要产物,而3-C-β-L-鼠李糖苷是通过3-C-α-L-鼠李糖苷的异构化而作为次要产物而产生的。可选地,2,3,4,6-四-O-苄基-α-D-甘露吡喃糖基氟与2,4-二苄基苯乙酰苯乙酮的反应得到了3-C-α-D-和3-C-β- D-甘露聚糖吡喃糖基苯乙酮衍生物在相同条件下。在反应过程中,通过3-C-α-D-甘露糖苷的异构化反应产生了3-C-β-D-甘露糖苷作为主要产物。这些组成上的差异显然是由于这些糖部分中C-3和C-5位置之间的1,3-双轴相互作用的大小引起的。