Naming systems aldehydes

There are no functional class names for aldehydes in the lUPAC system... 

Aldehydes are named using either the common system or the IUPAC system. Aldehyde common names are derived from the common names of the corresponding carboxylic acid. For example ... 

The IUPAC system employs a series of rules to formulate compound names. The following rules explain how to name aliphatic aldehydes ... 

Aldehydes, acids, and esters have roots for one and two carbons that are usually form- and acet-, rather than meth- and eth-, because these prefixes had been used so long they were grandfathered into the naming system (formaldehyde and acetic acid, rather than methanal and ethanoic acid). Departures from IUPAC nomenclature often occur for very common substances and, fortunately, they rarely can be misunderstood (ethyl alcohol instead of ethanol). 

Carotenoids that contain an oxygenated functionality are collectively referred to as xanthophylls. They retain the systematic naming system of carotenes, with the additional functionalities named according to the usual nomenclature rules previously discussed. For example, p,P-carotene-3,3 -diol (zeaxanthin) (Figure 3.10a). Methoxy, carboxy, aldehyde, epoxy, and ketone derivates are also common. 

There are two series of simple monosaccharides aldoses, which contain an aldehyde group, and ketoses, which contain a ketone group. Simple monosaccharides are also classified by the munber of carbon atoms which they contain e.g., trioses (3 C), tetroses (4 C), pentoses (5 C), and hexoses (6 C). The two naming systems are combined e.g., glucose is an aldohexose as it is a six-carbon monosaccharide with an aldehyde group. 

In the lUPAC system, aldehydes are named by selecting the longest chain that includes the carbonyl carbon. The -e of the alkane that has the same number of carbons is replaced by -al. Because the carbonyl carbon in aldehydes is always at the end of the chain, it is always designated as carbon number 1. 

The lUPAC system names the aldehyde of benzene as benzaldehyde. O... 

The lUPAC naming system for aldehydes uses the suffix -al. The parent chain is the longest chain containing the aldehyde group. Accordingly, the four-carbon aldehyde is called butanal because the name is derived from the alkane (butane) with the -e replaced by -al. The numbering of the chain starts at the carbon of the aldehyde group it is always at position one and need not be specified. Thus 3-chloro-2-methylbutanal is... 

When the aldehyde group is directly attached to a carbon atom of a ring system, the suffix -carbaldehyde is added to the name of the ring system, e.g., 2-naphthalenecarbaldehyde. When the aldehyde group is separated from the ring by a chain of carbon atoms, the compound is named (1) as a derivative of the acyclic system or (2) by conjunctive nomenclature, for example, (1) (2-naphthyl)propionaldehyde or (2) 2-naphthalenepropionaldehyde. 

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cycHc, the name is formed using carbaldehyde to indicate the functionaUty. The lUPAC system of aldehyde nomenclature drops the final e from the name of the parent acycHc hydrocarbon and adds al If two aldehyde functional groups are present, the suffix -dialis used. The prefix formjlis used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

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