Nomenclature of Aldehydes and ketones
We have already learnt the IUPAC system of nomenclature of organic compounds in XIth
standard. Let us apply the rules to name the following compounds.
Compound (common name, Structural
formula, IUPAC Name)
IUPAC Name
Prefix with position number
Root used
Primary suffix
Secondary Suffix
Formaldehyde
H – CHO
methanal
– meth ane/ al
Acetaldehyde
CH3 – CHO
ethanal
– eth ane/ al
Acrolein CH2 = CH – CHO
prop – 2- enal – prop 2-ena e/ al
Crotonaldehyde CH3 – CH = CH – CHO
but – 2 – enal – but 2-ena e/ al
Glyceraldehyde HO CH2 CH CHO
OH
2, 3 – dihydroxy propanal
2, 3 dihydroxy prop ane/ al
XII U12-Carbonyl Compounds.indd 146 2/19/2020 5:14:09 PM
| C ompound(common name, Structural formula, IUPAC Name) | IUPAC Name | |||
|---|---|---|---|---|
| Prex with position number | Rootused | Primar y sux | Secondar ySux | |
| FormaldehydeH – CHOmethanal | – | meth | ane/ | al |
| AcetaldehydeCH – CHOethanal3 | – | eth | ane/ | al |
| AcroleinCH = CH – CHOprop – 2- enal2 | – | prop | 2-ene/ | al |
| CrotonaldehydeCH – CH = CH – CHObut – 2 – enal3 | – | but | 2-ene/ | al |
| GlyceraldehydeHO CH CH CHOH22, 3 – dihydroxy propanal | 2, 3 dihydroxy | prop | ane/ | al |
147
Benzaldehyde CHO
phenyl methanal
phenyl meth ane/ al
Acetone / Dimethyl ketone CH3 – CO – CH3
propanone – prop ane/ one
Mesityl oxide
(CH3)2C = CHCOCH3
4 – methylpent-3-en-2-one
4 – methyl pent 3-ena e/ 2-one
Methyl Phenyl ketone C6H5 C CH3
O
Acetophenone (PIN)* 1-phenylethan-1-one
1-phenyl eth ane/ 1-one
Diphenyl ketone C6H5 C C6H5
O
Benzophenone (PIN)* Diphenylmethanone
Diphenyl meth ane/ one
CH3 CH2 C CH2
O
CHO
3 - oxopentanal
3 - oxo pent ane/ al
C H
COOH
O
2 – formylbenzoicacid
2 – formyl benz - oicacid
CH3
O
3 -methylcyclopent–2,4-dien-1-one
3 -methyl cyclopent 2, 4 diena e/ 1-one
* PIN– Preferred IUPAC name
XII U12-Carbonyl Compounds.indd 147 2/19/2020 5:14:12 PM
| B enzaldehydephenyl metChHaOnal | phenyl | meth | ane/ | al |
|---|---|---|---|---|
| Acetone / Dimethyl ketoneCH – CO – CHpropanone3 3 | – | prop | ane/ | one |
| Mesityl oxide(CH ) C = CHCO CH4 – methylpent-3-en-2-one3 2 3 | 4 – methyl | pent | 3-ene/ | 2-one |
| Methyl Phenyl ketoneC H CC HAcetophenone (PIN)*O1-phen6 y5 lethan-1-one | 1-phenyl | eth | ane/ | 1-one |
| Diphenyl ketoneC H CC HB enzo6 p5hen Oone (P 6 IN)*Diphenylmethanone | Diphenyl | meth | ane/ | one |
| OCH CH C CH CH3 - oxopentanal3 2 2 | 3 - oxo | pent | ane/ | al |
| OC H2 – formylbenzoCOO icHacid | 2 – formyl | benz | - | oicacid |
| O3 -methylcyclopent–2,4-dien-1-oCH ne3 | 3 -methyl | cyclopent | 2, 4 diene/ | 1-one |
148
Evaluate yourself
i) Write the IUPAC name for the following compound
i) CH3 CHO ii) (CH3)2 C = CHCOCH3
iii)
O
iv ) (CH3)2 C (OH) CH2 CHO
ii) Wrtie all possible structural isomers and position isomers for the ketone represented by the molecular formula C H O5 10 .