Nomenclature alkyl groups names

An alkyl group lacks one of the hydrogens of an alkane A methyl group (CH3 —) is an alkyl group derived from methane (CH4) Unbranched alkyl groups m which the point of attachment is at the end of the chain are named m lUPAC nomenclature by replac mg the ane endings of Table 2 2 by yl... 

The lUPAC rules permit alkyl halides to be named m two different ways called func twnal class nomenclature and substitutive nomenclature In functional class nomencla ture the alkyl group and the halide (fluoride chloride bromide or iodide) are desig nated as separate words The alkyl group is named on the basis of its longest continuous chain beginning at the carbon to which the halogen is attached... 

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... 

Section 16 1 Ethers are compounds that contain a C—O—C linkage In substitutive lUPAC nomenclature they are named as al/coxy derivatives of alkanes In functional class lUPAC nomenclature we name each alkyl group as a separate word (m alphabetical order) followed by the word ether... 

Alkylamines are named m two ways One method adds the ending amine to the name of the alkyl group The other applies the principles of sub stitutive nomenclature by replacing the e ending of an alkane name by amine and uses appropriate locants to identify the position of the ammo group Arylammes are named as derivatives of aniline... 

A single alkane may have several different names a name may be a common nfflne, or it may be a systematic name developed by a well-defined set of rules. The most widely used system is lUPAC nomenclature. Table 2.6 summarizes the rules for alkanes and cycloalkanes. Table 2.7 gives the r-ules for naming alkyl groups. 

TABLE D.4 Alkane Nomenclature Number of carbon atoms Formula Name of alkane Name of alkyl group... 

The IUPAC rules name esters as alkyl alkanoates. That is, the portion of the ester derived from the alcohol is named as an alkyl group. The portion of the ester that is derived from the carboxylic acid is named as the conjugate base of that acid. It is easy to distinguish these parts. The half derived from the carboxylic acid has the carbonyl group. Pentyl ethanoate, or pentyl acetate, is one ester used as artificial banana flavoring. Figure 11.51 shows three ester nomenclature examples. 

There are two ways of naming alkyl halides. The systematic (IUPAC) nomenclature treats an alkyl halide as an alkane with a halo- substituent Fluorine is fluoro-, chlorine is chloro-, bromine is bromo-, and iodine is iodo-. The result is a systematic haloalkane name, as in 1-chlorobutane or 2-bromopropane. Common or trivial names are constructed by naming the alkyl group and then the halide, as in isopropyl bromide. This is the origin of the term alkyl halide. Common names are useful only for simple alkyl halides, such as the following ... 

Common Names The common names of alkynes describe them as derivatives of acetylene. Most alkynes can be named as a molecule of acetylene with one or two alkyl substituents. This nomenclature is like the common nomenclature for ethers, where we name the two alkyl groups bonded to oxygen. 

The common name of an alcohol is derived from the common name of the alkyl group and the word alcohol. This system pictures an alcohol as a molecule of water with an alkyl group replacing one of the hydrogen atoms. If the structure is complex, the common nomenclature becomes awkward, and the IUPAC nomenclature should be used. 

IUPAC names use the more complex alkyl group as the root name, and the rest of the ether as an alkoxy group. For example, cyclohexyl methyl ether is named methoxycyclohexane. This systematic nomenclature is often the only clear way to name complex ethers. 

The simplest alkyne, HC = CH, named in the lUPAC system as ethyne, is more often called acetylene, its common name. The two-carbon alkyl group derived from acetylene is called an ethynyl group (HC=C-). Examples of alkyne nomenclature are shown in Figure 11.1. 

The Geneva system is a method of nomenclature which does not have this disadvantage since it is applicable to even the most complex hydrocarbons. To use this method it is first necessary to pick out the longest continuous chain of carbon atoms in the molecule and number them consecutively. The compound is considered to be a derivative of this longest continuous chain hydrocarbon. The various alkyl groups attached to this chain are named in the usual manner and their position is indicated by the number of the carbon atom to which they are joined. For example, for isopentane, there are four carbons in a... 

Present nomenclature of these core lipids and their variants or derivatives is cumbersome and trivial names appear to be required. Nishihara et al. [26] have suggested that diphytanylglycerol diether (structure 1, Fig. 1) and its variants (lA-lE, Fig. 1) be called archaeol (modified by adding the appropriate alkyl group designations, such as C20, C25, 3-hydroxy, etc.), and dibiphytanyldiglycerol tetraether (2) and its variant (2A) be called caldarchaeol and nonitolcaldarchaeol , respectively. This forms the basis of a useful and practical system of nomenclature for archaebacterial lipids, which will be followed here. 

The nomenclature follows two principles (7.) the ending ol is added to the name of the paraffin hydrocarbon (e. g. methanol), or (2.) the name of the corresponding alkyl group is placed before the word alcohol (e.g. methyl alcohol). 

The nomenclature of esters is similar to the nomenclature of the carboxylic acid salts. The alkyl group bonded to the oxygen atom is named first, then the -ic acid ending of the corresponding carboxylic acid is changed to -oate. 

A salt-type nomenclature is frequently used with alkyl halides in which the alkyl group s name precedes the name of the halide. In addition, halogen derivatives of methane have familiar non-systematic names. 

In common nomenclature, alcohols are often named with the alkyl group followed by alcohol (such as ethyl alcohol) and ethers are named using the names of the two alkyl groups followed by ether (such as diethyl ether). 

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