Epoxides and Ethers

Ethers have much lower boiling points than the corresponding isomeric alcohols because ethers cannot form intermolecular hydrogen bonds with themselves. They do, however, act as Lewis bases to form hydrogen bonds with compounds containing an -OH group (alcohols or water). 

Ethers are excellent solvents for organic compounds. Their relative inertness makes them good solvents in which to carry out organic reactions. 

Diethyl ether is prepared commercially by intermolecular dehydration of ethanol with sulfuric acid. The Williamson ether synthesis, another route to ethers, involves preparation of an alkoxide from an alcohol and a reactive metal, followed by an SN2 displacement between the alkoxide and an alkyl halide. 

Ethers can be cleaved at the C-0 bond by strong protonic (HBr) or Lewis (BBr3) acids. The products are alcohols and/or alkyl halides. 

Epoxides (oxiranes) are three-membered cyclic ethers. The simplest and commercially most important example is ethylene oxide, manufactured from ethylene, air, and a silver catalyst. In the laboratory, epoxides are most commonly prepared from alkenes and organic peroxy acids. 

Online homew/ork for this chapter can be assigned in OWL, an oniine homew/ork assessment tooi. 

Ethers are compounds that have two organic groups connected to a single oxygen atom. Epoxides are cyclic, three-membered ring ethers. 

Ethers are usually named by giving the name of each alkyl or aryl group, in alphabetical order, followed by the word ether. 

For ethers with more complex structures, it may be necessary to name the —OR group as an alkoxy group. In the lUPAC system, the smaller alkoxy group is named as a 

Ethers are colorless compounds with characteristic, relatively pleasant odors. They have lower boiling points (bp s) than alcohols with an equal number of carbon atoms. In fact, an ether has nearly the same bp as the corresponding hydrocarbon in which a —CH2— group replaces the ether s oxygen. The data in Table 8.1 illustrate these facts  

---

Thomson MOV/ Click Organic interactive o use a web-based palette to predict products from a variety of reactions involving ethers and epoxides. 

Yanagisawa, A. Yasue, K. Yamamoto. H. 7. Chem. Soc. Chem. Commun., 1994, 2103 Related Methods Ketones from Ethers and Epoxides (Section 174)... 

Halogenated Aromatic Compounds Halogenated Cresols Halogenated Ethers and Epoxides Halogenated Phenolic Compounds Halophenols Chlorophenol Dichlorophenol Halophenols Pentachlorophenol PCP Tetrachlorophenol Trichlorophenol... 

---