Common names of aldehydes

Common names of aldehydes are derived from the common names of the corresponding carboxylic acids (Table 18-2). These names often reflect the Latin or Greek term for the original source of the acid or the aldehyde. Greek letters are used with common names of aldehydes to give the locations of substituents. The first... 

The common names of aldehydes are derived from the names of the corresponding carboxylic acids by replacing ic acid by -aldehyde. 

Cerfain common names of familiar aldehydes are accepfable as lUPAC names A few examples include... 

It IS hard to find a class of compounds in which the common names of its members have influenced organic nomenclature more than carboxylic acids Not only are the common names of carboxylic acids themselves abundant and widely used but the names of many other compounds are derived from them Benzene took its name from benzoic acid and propane from propionic acid not the other way around The name butane comes from butyric acid present m rancid butter The common names of most aldehydes are derived from the common names of carboxylic acids—valeraldehyde from valeric acid for exam pie Many carboxylic acids are better known by common names than by their systematic ones and the framers of the lUPAC rules have taken a liberal view toward accepting these common names as permissible alternatives to the systematic ones Table 19 1 lists both common and systematic names for a number of important carboxylic acids... 

A cyanohydrin is an organic compound that contains both a cyanide and a hydroxy group on an aUphatic section of the molecule. Cyanohydrias are usually a-hydroxy nitriles which are the products of base-cataly2ed addition of hydrogen cyanide to the carbonyl group of aldehydes and ketones. The lUPAC name for cyanohydrias is based on the a-hydroxy nitrile name. Common names of cyanohydrias are derived from the aldehyde or ketoae from which they are formed (Table 1). 

Table 19.1 Common Names of Some Simple Aldehydes...

The aldehyde signature, -C-H (written also as -CHO, but never -COH), is always located at the end of the carbon chain. Common names for aldehydes are derived from the corresponding acid to which they are converted by further oxidation. The suffix ic acid is simply changed to -aldehyde ... 

Aldehydes use the parent name of their corresponding alkanes and the ending al. Therefore, the simplest aldehyde is meth-anal, but it goes by its common name formaldehyde. Aldehydes and ketones are often produced by the oxidation of alcohols. For example, formaldehyde is produced by the oxidation of methanol according to the following reaction ... 

If the hydroboration reaction is to be used to convert 1-alkynes into aldehydes, some way to stop the addition at the vinylborane stage is needed. The problem is that there is not enough steric hindrance at the end carbon of the vinylborane. The solution is to build extra steric hindrance into the other alkyl groups attached to the boron of the vinylborane. A borane, R2BH, with two bulky R groups already attached to the boron is used as the hydroboration reagent. One such reagent is prepared by the reaction of two equivalents of 2-methyl-2-butene (also known by the common name of isoamylene) with borane to produce a dialkylborane called di si amyl borane (a shortened version of diisoamylborane) ... 

The lUPAC names of aldehydes follow the usual pattern. The longest chain carrying the —CHO group is considered the parent structure and is named by replacing the -e of the corresponding alkane by -al. The position of a substituent is indicated by a number, the carbonyl carbon always being considered as C l. Here, as with the carboxylic acids, we notice that C-2 of the lUPAC name corresponds to alpha of the common name. 

Ethanal also has the common name acetaldehyde. Scientists often use the common names of organic compounds because they are so familiar to chemists. Because the carbonyl group in an aldehyde always occurs at the end of a carbon chain, no numbers are used in the name unless branches or additional functional groups are present. 

From the structures, write the common and I.U.P.A.C. names of aldehydes and ketones. 

The common names of the aldehydes are derived from the same Latin roots as the corresponding carboxylic acids. The common names of the first five aldehydes are presented in Table 14.1. 

The common name of an aldehyde is the same as the common name of the corresponding carboxylic acid (Section 17.1), except that aldehyde is substituted for ic acid (or oic acid ). When common names are used, the position of a substituent is designated by a lowercase Greek letter. The carbonyl carbon is not designated the carbon adjacent to the carbonyl carbon is the a-carbon. 

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