Ketones IUPAC nomenclature

In substitutive IUPAC nomenclature, cyanohydrins are named as hydroxy derivatives of nitriles. Because nitrile nomenclature will not be discussed until Section 20.1, we will refer to cyanohydrins as derivatives of the parent aldehyde or ketone as shown in the examples. This conforms to the practice of most chemists. 

Ketal is an acceptable subcategory term for acetals formed from ketones. It was dropped from IUPAC nomenclature, but continues to be so widely used that it has been reinstated. 

Ketones may also be named using functional class IUPAC nomenclature by citing the two groups attached to the carbonyl in alphabetical order followed by the word ketone. Thus, 3-methyl-2-butanone (substitutive) becomes isopropyl methyl ketone (functional class). 

Acetals formed from ketones are often called ketals, although this term has been dropped from the IUPAC nomenclature. 

A common name for the acetal of a ketone. The term ketal has been eliminated from the IUPAC nomenclature, (p. 855)... 

Nomenclature The most recent IUPAC nomenclature is stressed throughout the book, but common nomenclature is also discussed and used to develop students familiarity. Teaching only the IUPAC nomenclature might be justifiable in theory, but such an approach would handicap students in their further study and use of the literature. Much of the literature of chemistry, biology, and medicine uses common names such as methyl ethyl ketone, isovaleric acid, methyl tert-butyl ether, -y-aminobutyric acid, and e-caprolactam. This book emphasizes why systematic nomenclature is often preferred, yet it encourages familiarity with common names as well. 

A word about nomenclature. Once upon a time, chemists made a useful distinction between acetals (derived from aldehydes) and ketals (derived from ketones) which has since perished. The International Union of Pure and Applied Chemistry (IUPAC) decided (Rule C-331.1) that the term ketal is redundant and that the term acetal should now apply to all 1,1-to-ethers whether derived from aldehydes or ketones. Nevertheless, in A Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993 (R. Panico, W.H. Powel, I-C Richter, Eds. Blackwell Science Oxford, 1993) the IUPAC graciously reinstated the term ketal , by popular demand, as a subclass of the generic term acetals (Rule R-5.6,4),... 

In IUPAC nomenclature, the suffix for aldehydes is -al and for ketones, -one. The prefix for both is oxo. 

Reaction of an a-substituted enolate with an aldehyde or ketone can give two pairs of aldol dia-stereomers, which are conveniently designated as the syn form (17) and the anti form (18), where R2 is part of the parent chain in IUPAC nomenclature (equation 29). For simplicity, only one enantiomer of each pair will usually be shown throughout this section. The synlanti notation for aldol diastereomers has been described in detail by Heathcock.8... 

Appendix 1, Summary of IUPAC Nomenclature, continued E. Aromatic Ketones... 

Although substitutive names of the type just described are preferred, the IUPAC rules also permit ketones to be named by functional class nomenclature. The groups attached to the carbonyl group are named as separate words followed by the word ketone. The groups are listed alphabetically. 

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). 

The carbonyl group, C=0, is present in both aldehydes (RCH=0) and ketones (R2C=0). The IUPAC ending for naming aldehydes is -a/, and numbering begins with the carbonyl carbon. The ending for the names of ketones is -one, and the longest chain is numbered as usual. Common names are also widely used. Nomenclature is outlined in Sec. 9.1. 

The IUPAC rules for naming ketones append the suffix -one to the parent name. The position of the ketone carbon is indicated by a locant number. Figure 11.37 gives three nomenclature examples of ketones. The simplest ketone, propanone, is commonly known as acetone. Acetone is an excellent solvent for most organic compounds and is the main ingredient in fingernail polish remover. Acetone is one of the ketone bodies that build up in the bloodstream from excessive metabolism of fats. Because ketones typically have a sweet taste and odor, this can give a patient with ketosis a characteristic acetone breath. ... 

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