Naming alkanes

By combining the basic principles of lUPAC notation with the names of the various alkyl groups we can develop systematic names for highly branched alkanes We 11 start with the following alkane name it then increase its complexity by successively adding methyl groups at various positions... 

Diols are almost always given substitutive lUPAC names As the name of the prod uct m the example indicates the substitutive nomenclature of diols is similar to that of alcohols The suffix dwl replaces ol and two locants one for each hydroxyl group are required Note that the final e of the parent alkane name is retained when the suffix begins with a consonant ( diol) but dropped when the suffix begins with a vowel ( ol)... 

The longest continuous chain that contains the —CH group provides the base name for aldehydes The e ending of the corresponding alkane name is replaced by al and sub stituents are specified m the usual way It is not necessary to specify the location of O... 

The e ending of an alkane name is dropped before a suffix beginning with a vowel ( a/) and retained before one beginning with a consonant ( dial)... 

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... 

Straight-chain alkanes are named according to the number of carbon atoms they contain, as shown in Table 3.3. With the exception of the first four compounds—methane, ethane, propane, and butane—whose names have historical roots, the alkanes are named based on Greek numbers. The suffix -one is added to the end of each name to indicate that the molecule identified is an alkane. Thus, pentane is the five-carbon alkane, hexeme is the six-carbon alkane, and so on. We ll soon see that these alkane names form the basis for naming all other organic compounds, so at least the first ten should be memorized. 

Alkane Name Alkyl group Name (abbreviation)... 

When writing an alkane name, the nonhyphenated prefix iso- is considered part of the alkyl-group name for alphabetizing purposes, but the hyphenated and italicized prefixes sec- and tert- are not. Thus, isopropyl and isobutyl are listed alphabetically under i, but sec-butyl and ferf-butyl are listed under b. 

Aldehydes are named by replacing the terminal -e of the corresponding alkane name with -at. The parent chain must contain the -CHO group, and the -CHO carbon is numbered as carbon 1. For example ... 

Compounds containing the -C=N functional group are called nitriles and undergo some chemistry similar to that of carboxylic acids. Simple open-chain nitriles are named by adding -nitrile as a suffix to the alkane name, with the nitrile carbon numbered Cl. 

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

In Method 2, described by Rule A-31, the saturated cyclic parent is named as a polycyclo-[.. jalkane. The alkane name identifies the total number of carbon atoms in the ring system. The names bicyclo, tricyclo, tetracyclo, etc. identify parent compounds of two, three, four, etc. rings. Double bonds in the ring are identified by names such as w-alkenc, ,/w-alkadicne, where the n and m give the position of the double bond. Substituents consist of alkyl, cycloalkyl, phenyl, etc. radicals. 

This number indicates the number of the first carbon atom that is part of the double/triple bond. (2) The name of longest carbon chain is formed by taking the alkane name, dropping the -ane suffix and replace it by -ene for an alkene or -yne for an alkyne. 

Step 1 Choose the longest alkyl group as the parent alkane. Give it an alkane name. 

Using a quick and easy scheme for naming any compound Introducing alkane naming conventions... 

Other types of alkanes include closed circles and branched chains, but we discuss the straight-chain alkanes here because they make clecir the basic strategy for naming hydrocarbons. From the standpoint of nciming, the hydrogen atoms in a hydrocarbon are more or less filler atoms. Alkanes names cire based on the largest number of consecutively bonded carbon atoms, so the ncime of a hydrocarbon tells you about that molecule s structure. 

RC N Nitrile CH,C N Acetonitrile or Ethanenitrile -ic or -oic acid to nitrile or add -nitrile to alkane name... 

Alcohols are named by identifying the point of attachment of the -OH group to the hydrocarbon chain and using the suffix -ol to replace the terminal -e in the alkane name. Numbering of the chain begins at the end nearer the -OH group. For example,... 

Alkyl halides are named using the IUPAC rules for alkanes. Naming the alkyl group attached to the halogen and adding the inorganic halide name for the halogen atom creates common names. 

Pick out the longest continuous chain to which the hydroxyl group is directly attached. The parent name of the alcohol comes from the alkane name for the same chain length. Drop the -e ending and add -ol. 

The parent name comes from the alkane name of the same number of carbons. 

The five IUPAC rules previously outlined in the Nomenclature section for aldehydes also apply to ketones, with one exception After dropping the -e ending of the alkane name, you add -one for ketones (rather than -al, which designates aldehydes). 

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