91影视

Hydroxy groups of sugar can be converted to methyl ethers by treating with methyl iodide (CH₃I) and silver oxide (Ag₂O). CH₃-I group can be polarised by silver oxide (Ag₂O), which makes the methyl carbon more strongly electrophilic. Attack by the -OH group of carbohydrate is then followed by deprotonation which gives the ether.

Pyranose is a six-membered cyclic hemiacetal while a furanose is a five-membered cyclic hemiacetal.

1. 伪-顿-蹿谤耻肠迟辞蹿耻谤补苍辞蝉别 on treatment with excess methyl iodide and silver oxide gives methyl 2,3,4,6, -tetra-O-methyl-伪-D-fructofuranoside as the product.
   
2. 尾-顿-驳补濒补肠迟辞辫测谤补苍辞蝉别 on treatment with excess methyl iodide and silver oxide gives methyl 2,3,4,6,-tetra-O-methyl-尾-D-galactopyranoside as the product.