对硝基苯基-α-D-吡喃甘露糖苷的合成

Synthesis of p-Nitrophenyl α-D-Mannopyranoside

摘要:

以D-甘露糖为原料，通过乙酰化、Helferich糖苷化、脱保护3步反应，简便地合成了对硝基苯基-α-D-吡喃甘露糖苷。通过正交实验探讨了反应物摩尔比、温度、预先减压时间、反应时间以及催化剂的量对Helferich糖苷化立体选择性和产率的影响。得到最佳反应条件为：1,2,3,4,6-五-O-乙酰基-D-甘露糖2.56 mmol，1,2,3,4,6-五-O-乙酰基-D-甘露糖与对硝基苯酚摩尔比1:4，催化剂SnCl4用量0.308 mmol，预先负压时间和反应时间均为80 min，反应温度为120 ℃，在该条件下，Helferich糖苷化反应的α-立体选择性最好，产率可达72.4%。

Abstract:

In this paper, p-nitrophenyl α-D-mannopyranoside was readily synthesized with D-mannose as starting material by acetylation, Helferich glycosidation and deacetylation. The effect of mole ratio of reactants, temperature, decompression time, reaction time and the amount of catalyst on stereoselectivity and the yield of Helferich glycosidation was investigated through orthogonal experiment. The results show that the highest yield of 72.4% for the optimal α-stereoselectivity of Helferich glycosidation were based on 2.56 mmol of 1,2,3,4,6-Penta-O-acetyl-D-mannopyranose, with the molar ratio of 1,2,3,4,6-Penta-O-acetyl-D-mannopyranose to p-nitrophenol being 1:4, dosage of catalyst SnCl4 being 0.308 mmol, time of decompression and reaction being 80 min and the temperature being 120 ℃.