QJEEM19Che2f5: JEE Main 2019 Chemistry - Class 11 JEEM19Che2f5 Solution: The IUPAC name of the following compound is :

Note :

1. Here -OH and -COOH functional group present. And priority of -COOH group is higher so numbering start from -COOH group.

2. Here -COOH acts as main functional group and -OH acts as substitute. So we take prefix of -OH group (Hydroxy) and suffix of -COOH group (-oic acid).

3. Here two substitude -CH₃(methyl) and -OH(Hydroxy) present. And 'H' of Hydroxy comes before 'm' of methyl in alphabetical order. So IUPAC name stars with Hydroxy substitude.

	Functional group (priority order)	suffix(s)	prefix
(1)		Oic acid(when carbon(C) of this functional group present in the main chain) or Carboxylic acid (when carbon(C) of this functional group is not present in the main chain)	Carboxy
(2)		sulphonic acid	sulpho
(3)		Oic anhydrid (when carbon(C) of this functional group present in the main chain) or Carboxylic anhydride (when carbon(C) of this functional group is not present in the main chain)	$$-$$
(4)		Oate (when carbon(C) of this functional group present in the main chain) or Carboxylate (when carbon(C) of this functional group is not present in the main chain)	$$-$$
(5)		Oyl halide (when carbon(C) of this functional group present in the main chain) or Carboxyl halide (when carbon(C) of this functional group is not present in the main chain)	haloflormyl
(6)		amide (when carbon(C) of this functional group present in the main chain) or carbamide (when carbon(C) of this functional group is not present in the main chain)	carbamoyl
(7)	cynide ($$-$$ C $$\equiv$$ N)	nitrile (when carbon(C) of this functional group present in the main chain) or carbonitrile (when carbon(C) of this functional group is not present in the main chain)	cyano
(8)		Carbylamine	isocyano
(9)		al (when carbon(C) of this functional group present in the main chain) or Carbaldehyde (when carbon(C) of this functional group is not present in the main chain)	formyl (oxo)
(10)		one	oxo
(11)	$$-$$ OH	ol	hydroxy
(12)	$$-$$ SH	thiol	mercapto
(13)	$$-$$ NH$${}_2$$	amine	amino

From this table you can see -COOH has highest priority and -NH₂ has lowest priority among all functional groups.