Synthesis of C-glycopyranosylphloroacetophenone derivatives and their anomerization facilitated by 1,3-diaxial interactions
作者:Toshihiro Kumazawa、Kanako Onda、Hayato Okuyama、Shigeru Matsuba、Shingo Sato、Jun-ichi Onodera
DOI:10.1016/s0008-6215(02)00069-1
日期:2002.6
dictated primarily by the preference of the bulky aromatic aglycon to orient equatorially, due to the strong repulsion of the aglycon. The anomerization is directed secondarily by the presence of 1,3-diaxial interactions in the sugar moiety.
2,3,4-三-O-苄基-6-脱氧-α-D-吡喃葡萄糖基氟,2,3,4,6-四-O-苄基-α-D-吡喃戊二酰氟和2的反应在三氟化硼二乙基醚化物的存在下,将3,4-三-O-苄基-α-L-呋喃果糖基氟与2,4-二-O-苄基苯乙酮形成氟,分别得到相应的3-C-β-D-糖吡喃糖基乙酰基苯乙酮衍生物,完全呈异源纯净形式。或者,使2,3,4,6-四-O-苄基-α-D-吡咯烷酰氟与2,4-二-O-苄基苯乙酰苯乙酮反应,可同时获得3-C-β-D-戊吡喃糖基苯乙酰苯酮衍生物(4C (1)构象)为主要产物,而3-C-α-D-戊吡喃基酰基苯乙酮衍生物(1C(4)构象)为次要产物,在相同条件下。包括先前制备的C-糖基氯苯乙酮衍生物,其中包含3-C-β-D-葡萄糖基,3-C-β-D-木糖基,3-C-β-2-脱氧-D-阿拉伯糖基-己糖基,3-C- β-D-半乳糖基,3-C-β-L-阿拉伯糖基和3-C-α-L-阿拉伯糖