Nomenclature of Aldehydes and ketones

12.1 Nomenclature of Aldehydes and ketones#

We have already learnt the IUPAC system of nomenclature of organic compounds in \(XI^{\mathrm{th}}\) 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-ene	al
Crotonaldehyde CH₃ – CH = CH – CHO but – 2 – enal	—	but	2-ene	al
Glyceraldehyde HO — CH₂ — CH — CHO                    |                  OH 2, 3 – dihydroxy propanal	2, 3 dihydroxy	prop	ane	al
Benzaldehyde 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-ene	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 Benzophenoxe (PIN)* Diphenylmethanone	Diphenyl	meth	ane	one
O                   || CH₃— CH₂ — C — CH₂ —CHO 3 - oxopentanal	3 - oxo	pent	ane	al
2 – formylbenzoicacid	2 – formyl	benz	-	oicacid
3 -methylcyclopent–2,4-dien-1-one	3 -methyl	cyclopent	2, 4 diene	1-one

Evaluate yourself

i) Write the IUPAC name for the following compound

i)

ii) $(\text{CH}_3)_2\text{C}=\text{CHCOCH}_3$

iii)

iv) $(\text{CH}_3)_2\text{C}(\text{OH})\text{CH}_2\text{CHO}$

ii) Wrtie all possible structural isomers and position isomers for the ketone represented by the molecular formula C₅H₁₀O.