Highly practical synthesis of gastrodin has been developed using
penta-O-acetyl-b-D-glucopyranose and p-cresol as glycosyl donor and glycosyl
acceptor, respectively, in four steps with 58.1% overall yield. At the
initial step, the penta-O-acetyl-b-D-glucopyranose was treated with p-cresol
in the presence of BF3.Et2O as catalyst to generate 4-methylphenyl
2,3,4,6-tetra-O-acetyl-b-D-glucopyranoside in 76.3% yield. Furthermore, this
product was subjected to radical bromination with NBS to provide
4-(bromomethyl) phenyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyranoside in 91%
yield. Subsequently, reaction of 2,3,4,6-tetra-O-acetyl-b-D-glucopyranoside
with a solution of acetone and saturated aqueous sodium bicarbonate led to
4-(hydroxylmethyl) phenyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyranoside in 93%
yield. Finally, global deprotection of 4-(hydroxylmethyl) phenyl
2,3,4,6-tetra-O-acetyl-b-D-glucopyranoside under Zemplen conditions
furnished gastrodin in 90% yield. Compared to the previously reported
methods, this protocol has advantages of operational simplicity,
chromatography-free separation, high overall yield, inexpensive and common
reagents as well as less waste pollutants, rendering it an alternative
suitable for industrial production.
使用五-O-乙酰基-b-
D-吡喃葡萄糖和
对甲酚作为糖基供体和糖基,开发出了非常实用的
天麻素合成方法。
五-O-乙酰基-b-
D-吡喃葡萄糖和
对甲酚分别作为糖基供体和糖基受体,通过四个步骤合成了
天麻素,总产率为 58.1%。
受体,分四个步骤合成了
天麻素,总收率为 58.1%。在
在第一步,五-O-乙酰基-b-
D-吡喃葡萄糖与
对甲酚在
BF3.
在 .Et2O 催化剂存在下,生成 4-甲基苯基
2,3,4,6-四-O-乙酰基-b-
D-吡喃葡萄糖苷,产率为 76.3%。此外,这种
用
NBS 进行自由基
溴化反应,得到
4-(
溴甲基)苯基 2,3,4,6-O-四乙酰基-b-
D-吡喃葡萄糖苷,收率为 91%。
收率为 91%。随后,2,3,4,6-O-四乙酰基-b-
D-吡喃葡萄糖苷与
丙酮和饱和的
与
丙酮和饱和
碳酸氢钠水溶液反应,生成了
4-(羟甲基)苯基 2,3,4,6-O-四乙酰基-b-
D-吡喃葡萄糖苷,收率为 93%。
收率为 93%。最后,对 4-(羟甲基)苯基
2,3,4,6-四-O-乙酰基-b-
D-吡喃葡萄糖苷的全脱保护反应。
得到
天麻素,产率为 90%。与之前报道的方法相比
相比,该方法具有操作简单、无需色谱分离、总体收率高的优点、
操作简单、无需色谱分离、总收率高、试剂廉价且普通
试剂以及较少的废弃污染物,因此是一种适合工业生产的替代方法。
适合工业化生产。