CHAPTER SIXTEEN Ethers, Epoxides, and Sulfides Ethers are described as symmetrical or unsymmetrical depending on whether the two groups bonded to oxygen are the same or different Unsymmetrical ethers are also called mixed ethers. Diethyl ether is a symmetrical ether; ethyl methyl ether is an unsymmet rical ether Cyclic ethers have their oxygen as part of a ring-they are heterocyclic compounds (Section 3. 15). Several have specific IUPAC names. Oxirane Oxolane Oxane (Ethylene oxide) (Tetrahydrofuran) (Tetrahydropyran) Recall from Section 6.18 that In each case the ring is numbered starting at the oxygen. The IUPAC rules also permit epoxides oxirane(without substituents)to be called ethylene oxide. Tetrahydrofuran and tetrahy -epoxy derivatives of alkanes dropyran are acceptable synonyms for oxolane and oxane, respectivel n substitutive IUPAC nomen. clature PROBLEM 16.1 Each of the following ethers has been shown to be or is sus- pected to be a mutagen, which means it can induce mutations in test cells. Write he structure of each of these ethers (a) Chloromethyl methyl ether (b)2-(Chloromethyl)oxirane(also known as epichlorohydrin) SAMPLE SOLUTION (a)Chloromethyl methyl ether has a chloromethyl group (CICH2-)and a methyl group (CH3)attached to oxygen. Its structure is Many substances have more than one ether linkage. Two such compounds, often used as solvents, are the diethers 1, 2-dimethoxyethane and 1, 4-dioxane. Diglyme, also CH3OCH2CH2OCH3 CH3OCH2CH2OCH2CH2OCH3 Molecules that contain several ether functions are referred to as polyethers. Polyethers have received much recent attention, and some examples of them will appear in Section 16.4 Sulfides are so The sulfur analogs(rs-)of alkoxy groups are called alkylthio groups. The first two of the following examples illustrate the use of alkylthio prefixes in substitutive thioethers, but this term is nomenclature of sulfides. functional class iupac names of sulfides are derived not part ot systematic iUPAc exactly the same way as those of ethers but end in the word"sulfide. Sulfur heterocy les have names analogous to their oxygen relatives, except that ox-is replaced by thi. Thus the sulfur heterocycles containing three-, four-, five, and six-membered rings are named thiirane, thietane, thiolane, and thane, respectively CH3CH2SCH, CH3 Ethylthioethane (Methylthio Thiirane Diethyl sulfide Back Forward Main MenuToc Study Guide ToC Student o MHHE WebsiteEthers are described as symmetrical or unsymmetrical depending on whether the two groups bonded to oxygen are the same or different. Unsymmetrical ethers are also called mixed ethers. Diethyl ether is a symmetrical ether; ethyl methyl ether is an unsymmet￾rical ether. Cyclic ethers have their oxygen as part of a ring—they are heterocyclic compounds (Section 3.15). Several have specific IUPAC names. In each case the ring is numbered starting at the oxygen. The IUPAC rules also permit oxirane (without substituents) to be called ethylene oxide. Tetrahydrofuran and tetrahy￾dropyran are acceptable synonyms for oxolane and oxane, respectively. PROBLEM 16.1 Each of the following ethers has been shown to be or is sus￾pected to be a mutagen, which means it can induce mutations in test cells. Write the structure of each of these ethers. (a) Chloromethyl methyl ether (b) 2-(Chloromethyl)oxirane (also known as epichlorohydrin) (c) 3,4-Epoxy-1-butene (2-vinyloxirane) SAMPLE SOLUTION (a) Chloromethyl methyl ether has a chloromethyl group (ClCH2±) and a methyl group (CH3±) attached to oxygen. Its structure is ClCH2OCH3. Many substances have more than one ether linkage. Two such compounds, often used as solvents, are the diethers 1,2-dimethoxyethane and 1,4-dioxane. Diglyme, also a commonly used solvent, is a triether. Molecules that contain several ether functions are referred to as polyethers. Polyethers have received much recent attention, and some examples of them will appear in Section 16.4. The sulfur analogs (RS±) of alkoxy groups are called alkylthio groups. The first two of the following examples illustrate the use of alkylthio prefixes in substitutive nomenclature of sulfides. Functional class IUPAC names of sulfides are derived in exactly the same way as those of ethers but end in the word “sulfide.” Sulfur heterocy￾cles have names analogous to their oxygen relatives, except that ox- is replaced by thi-. Thus the sulfur heterocycles containing three-, four-, five-, and six-membered rings are named thiirane, thietane, thiolane, and thiane, respectively. CH3CH2SCH2CH3 Ethylthioethane Diethyl sulfide SCH3 (Methylthio)cyclopentane Cyclopentyl methyl sulfide S Thiirane CH3OCH2CH2OCH3 1,2-Dimethoxyethane O O 1,4-Dioxane CH3OCH2CH2OCH2CH2OCH3 Diethylene glycol dimethyl ether (diglyme) 1 O 2 3 Oxirane (Ethylene oxide) O Oxetane O Oxolane (Tetrahydrofuran) O Oxane (Tetrahydropyran) 620 CHAPTER SIXTEEN Ethers, Epoxides, and Sulfides Recall from Section 6.18 that epoxides may be named as -epoxy derivatives of alkanes in substitutive IUPAC nomen￾clature. Sulfides are sometimes in￾formally referred to as thioethers, but this term is not part of systematic IUPAC nomenclature. Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website