Prefixes ethers

Ethers are named m substitutive lUPAC nomenclature as alkoxy derivatives of alkanes Functional class lUPAC names of ethers are derived by listing the two alkyl groups m the general structure ROR m alphabetical order as separate words and then adding the word ether at the end When both alkyl groups are the same the prefix di precedes the name of the alkyl group... 

Although epoxides are always considered to have their oxygen atom as part of a three membered ring the prefix epoxy in the lUPAC system of nomenclature can be used to denote a cyclic ether of vanous sizes Thus... 

Ethers (R —O—R ). In substitutive nomenclature, one of the possible radicals, R—O—, is stated as the prefix to the parent compound that is senior from among R or R. Examples are methoxyethane for CH3OCH2CH3 and butoxyethanol for C4Hc,0CH2CH20H. 

For oximes, the word oxime is placed after the name of the aldehyde or ketone. If the carbonyl group is not the principal group, use the prefix hydroxyimino-. Compounds with the group Z = N—OR are named by a prefix alkyloxyimino- as oxime O-ethers or as O-substituted oximes. Compounds with the group r C=N(0)R are named by adding A-oxide after the name of the alkylideneaminc compound. For amine oxides, add the word oxide after the name of the base, with locants. For example, C5H5N—O is named pyridine A-oxide or pyridine 1-oxide. 

Simple ethers derive their name from the two groups attached to the oxygen followed by the word ether, eg, diethyl ether, CH3CH2OCH2CH3. Eor symmetrical ethers the "di" prefix is often omitted. If one group has no simple name, the compound may be named as an alkoxy derivative, eg, 2-ethoxyethanol, CH3CH2OCH2CH2OH. 

The simplest of the ethers would be ether that has the simplest hydrocarbon backbones attached those backbones are the radicals of the simplest hydrocarbon, methane. Therefore, the simplest of the ethers is dimethyl ether, whose formula is CH3OCH3. Dimethyl is used because there are two methyl radicals, and di-" is the prefix for two. This compound could also be called methyl methyl ether, or just... 

A fluonnated dimethyl ether is assigned the same number as the corresponding Cj alkane prefixed with an "E , a nomenclature recently adopted by the National Institute of Science and Technology (NIST) in the United States... 

An intramolecular ether (commonly called an intramolecular anhydride), formally arising by elimination of water from two hydroxy groups of a single molecule of a monosaccharide (aldose or ketose) or monosaccharide derivative, is named by attaching the (detachable) prefix anhydro- preceded by a pair of locants identifying the two hydroxy groups involved. 

Cyclic ethers can be named simply as oxacycloalkanes, such as oxacyclopropane, oxacyclo-butane, oxacyclopentane, and oxacyclohexane, where the prefix oxa indicates the replacement of CH2 by O in corresponding cycloalkanes. Most cyclic ethers, however, are known by other names. The 3-, 4-, 5-, and 6-membered rings are oxirane, oxetane, oxolane, and oxane, respectively, or ethylene oxide (or epoxide), trimethylene oxide, tetrahydrofuran, and tetrahydropyran. 

For example, substitution can be made on an oxygen atom in the case of esters and ethers. It is characterised by the symbol O, which is placed after the locant. The compound prefix deoxy- is composed of the prefixes de-, meaning without in subtractive nomenclature, and oxy-, to indicate the subtraction of an oxy group from an -OH group C-O-H C-H. Such an operation is needed when an -OH group is replaced by another group, such as an amino group. 

Problem 14.61 Ethers, especially those with more than one ether linkage, are also named by the oxa method. The ether O s are counted as C s in determining the longest hydrocarbon chain. The O is designated by the prefix oxa-, and a number indicates its position. Use this method to name ... 

Ethers can be symmetrical, where the two alkyl groups are the same, or unsymmetrical, where the two alkyl groups are different. While diethyl ether is symmetrical, ethyl methyl ether is unsymmetrical. The common name of an unsymmetrical ether is obtained by quoting the names of the two alkyl groups in alphabetical order followed by the prefix ether. 

In the nomenclature of ethers, either the suffix -ether or the prefix alkoxy- is used. For example, diethyl ether can be called ethoxyethane, and methyl t-butyl ether can be named as 2-methyl-2-methoxypropane. 

Three-membered cychc ethers are known as epoxides. They are just a subclass of ethers containing a three-membered oxirane ring (C—O—C unit). Cyclic ethers have the prefix epoxy- and suffix -alkene oxide. Five-membered and six-membered cyclic ethers are known as oxolane and oxane, respectively. 

The classes listed in Table 1-12 are families which exhibit the same regularity of boiling points, melting points, densities, and other properties seen in the hydrocarbon families we have already studied. Some of the families are named with characteristic suffixes while others have prefixes, or even separate words-in the names. For instance, alcohols are named with the suffix -ol. Ketones are named with the suffix -one. Amine and nitriles are named with the full suffix according to the family name. Ethers and halides usually have the full family name as a separate word, and nitro- and organometallic compounds have the prefix nitro- or the prefix corresponding to the hydrocarbon part of the organometallic molecule. 

Positional Isomers Positional isomers differ in the position where a functional group occurs in a molecule. In Figure 1.2.1, 1-butanol and 2-butanol are positional isomers with the position of the hydroxyl group indicated by the prefixes 1 and 2, respectively. Similarly, methyl n-propyl ether and diethyl ether are positional isomers, as reflected in their synonym names 2-oxapentane and 3-oxapentane, with the prefixes 2 and 3 indicating the position of the ether group, respectively. 

In the common nomenclature for ethers, each of the R groups in R—O—R is named as a separate word, except when the groups are identical, in which case the prefix di or bis may be used (di is used for simple groups, bis for substituted groups) ... 

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