Ester and Ether Formation
The -OH groups on a monosaccharide can be readily converted to esters and ethers. Esterfication can be done with an acid chloride or acid anhydride while treatment with an alkyl halide by a Williamson ether synthesis leads to the ether.
Acetal derivatives formed when a monosaccharide reacts with an alcohol in the presence of an acid catalyst are called glycosides. This reaction is illustrated for glucose and methanol in the diagram below. In naming of glycosides, the "ose" suffix of the sugar name is replaced by "oside", and the alcohol group name is placed first. As is generally true for most acetals, glycoside formation involves the loss of an equivalent of water. The diether product is stable to base and alkaline oxidants such as Tollen's reagent. Since acid-catalyzed aldolization is reversible, glycosides may be hydrolyzed