Nomenclature: Acids, Esters, Aldehydes, and Ketones

1. Nomenclature:Acids, Esters, Aldehydes, and Ketones SCH4U0

2. Nomenclature Rules • When naming organic molecules that contain several different functional groups, we have a set of rules to determine how to name the molecule • What group is named as the main compound and what groups are substituents • We have a priority list for all of the functional groups (next slide) • When naming, the longest chain containing the highest priority group is the main compound name

3. Functional Group Priority List Carboxylic Acid Ester Amide Aldehyde Ketone Alcohol Amine Alkene / Alkyne Alkane Ether / Alkyl Halide / Nitro

4. Carboxylic Acids • Carboxylic acids contain the group on the right • Most organic acids contain this group • Eg: citric acid, ascorbic acid, acetic acid, etc… • When naming: • Molecule gets “-oic acid” suffix • Highest priority group, thus always named as the main chain • Always on a terminal carbon, thus it doesn’t need to be numbered ethan oic acid pentan oic acid common name: acetic acid

5. Carboxylic Acids • Name the following molecules • Draw the following molecules propadioic acid butanoic acid octanoic acid ethadioic acid common name: oxalic acid

6. Naming With Multiple Groups • When a compound has several functional groups • The highest priority group is used as the main name • The molecule is numbered to give the highest priority group the smallest numbers • All other groups are listed alphabetically 3 – ethyl - 5 – en - oic acid hex 4,5 – dimethyl hexanoic acid

7. Esters • Esters contain the functional group on the right • Many esters give off strong fragrances (perfumes, fruit, vegetables, etc…) • Many synthetic and natural compounds contain esters • Eg: polyester, lipids, vitamin C, etc… • When naming; • Use the suffix “-oate” for the alkyl group containing the carbonyl carbon • Name the alkyl group attached to the oxygen as an alkyl substituent carbonyl group methyl pentanoate

8. Esters • Name the following molecules • Draw the following molecules propyl butanoate phenyl hexanoate ethyl pentanoate cyclopentylbutanoate

9. Aldehydes and Ketones • Aldehydes and Ketones are very similar, they both contain carbonyl groups • An aldehyde has the carbonyl on a terminal carbon • A ketone has the carbonyl on a secondary carbon • When naming; • Aldehydes get the “-al” suffix • Ketones get the “-one” suffix butan al pent one - 3 - Old: 3 - pentanone

10. Aldehydes and Ketones • Since aldehydes are only on terminal carbons, they do not have to be numbered • Ketones must be numbered, unless the positioning of the ketone is obvious • Name the following molecules butadial butanone methanal propanone Common name: acetone Common name: Formaldehyde

11. Aldehydes and Ketones • Name the molecules below • Draw the following molecules 3,4,4-trimethylpent-2-one 3-ethyl-2,4-dimethylpentanal 3-ethyl-2-methylhept-4-one 2,2-diethyl-3-propylhexadial