Ethers / Alkoxy group containing compounds
The alkoxy group is an alkyl group which is singularly bonded to oxygen. An alkoxy or aryloxy group bonded to an alkyl or aryl is an ether. Ethers can be symmetrical or unsymmetrical, cyclic or acyclic. Ethers can be prepared by dehydration of alcohols, nucleophilic displacement of organic halides by alkoxides (Williamson ether synthesis, Ullmann condensation), electrophilic addition of alcohols to alkenes and many other methods. Oxiranes are special class of cyclic three-atom ring ethers, which are strained, and hence highly reactive. Ring-opening reactions dominate the reactivity of epoxides. Ether group in general is weakly reactive for further transformations but it is frequently present in all kinds of organic compounds. Some ethers (methoxymethyl, tetrahydropyranyl, allyl, t-butyl, benzyl and silyl ethers) are widely used to prepare protected hydroxy groups. Polyethers are very important polymers in industry (PEG, PPG etc.).