Synthesis of a methyl heptaglucoside: Analogue of the phytoalexin elicitor from phytophtora megasperma
作者:R. Verduyn、M. Douwes、P.A.M. van der Klein、E.M. Mösinger、G.A. van der Marel、J.H. van Boom
DOI:10.1016/s0040-4020(01)87208-2
日期:1993.8
The ethylthio-laminaribioside 29, prepared by regiospecific glycosylation of ethyl 4,6-O-benzylidene-1-thio-β-d-glucopyranoside (9) with 2,3,4,6-tetra-O-benzoyl-d-glucopyranosyl imidate 17 and subsequent benzoylation, could be elongated in a step-wise fashion by consecutive iodonium ion promoted condensations with methyl 2,3,4-tri-O-benzoyl-α-d-glucopyranoside (5), ethyl 2,3,4-tri-O-benzoyl-6-O-te
所述乙硫基laminaribioside 29,由乙基4,6-区域专一的糖基化制备ø -亚苄基-1-硫代-β-β-d-D-吡喃葡萄糖苷(9)与2,3,4,6-四- ö苯甲酰基d-D-吡喃葡萄糖可以通过连续的碘鎓离子促进与2,3,4-甲基-三-O-苯甲酰基-α-d-吡喃葡萄糖苷(5),2,3,4乙基的连续碘鎓离子促进的缩合反应逐步延长亚氨酸酯17和随后的苯甲酰化作用-三ø -苯甲酰基-6- ø -叔丁基二-1-硫代β-d-D-吡喃葡萄糖苷(7),所述laminaribioside 29和乙基2,3,4,6-四ö-苯甲酰基-1-硫代-β-d-吡喃葡萄糖苷(8),和间歇性的保护基操作,以产生部分酰化的七糖36。最后,支链七聚体中的一个步骤的脱酰化36,得到目标化合物α-3- 2,3 4 -二-β-d-glucopyranosylgentiopentaoside(2)。