Write IUPAC name of the following compounds: (i) $CH_3-CH(CH_3)-CH(OH)-C(CH_3)_2-CH_3$ (ii) $HO-CH_2-CH(OH)-CH_2OH$ (iii) $H_3C-CH_2-O-CH(CH_3)-CH_2-CH_3$ (iv) 2,6-dimethylphenol (a benzene ring bearing an $-OH$ group with a $-CH_3$ group at each of the two ortho positions) (v) $

Question

Write IUPAC name of the following compounds: (i) $CH_3-CH(CH_3)-CH(OH)-C(CH_3)_2-CH_3$ (ii) $HO-CH_2-CH(OH)-CH_2OH$ (iii) $H_3C-CH_2-O-CH(CH_3)-CH_2-CH_3$ (iv) 2,6-dimethylphenol (a benzene ring bearing an $-OH$ group with a $-CH_3$ group at each of the two ortho positions) (v) $H_3C-CH(Cl)-CH(CH_3)-CH(CH_3)-CH_2OH$

**OR**

Predict the products obtained in the following reactions: (i) $C_6H_5-OC_2H_5$ (ethoxybenzene) $+ HBr \longrightarrow$ (ii) $C_6H_5-OC_2H_5$ (ethoxybenzene) $\xrightarrow{	ext{conc. } H_2SO_4 / 	ext{conc. } HNO_3}$ (iii) $H_3C-CH=CH_2 \xrightarrow{H_2O/H^+}$ (iv) $H_3C-CH_2-CH(CH_3)-CHO \xrightarrow{NaBH_4}$ (v) benzene-1,2-dicarboxylic acid, $o	ext{-}C_6H_4(COOH)_2$ $\xrightarrow{SOCl_2,\ 	ext{Temp.}}$

Accepted Answer

>

> [!TLDR]
> Number each parent chain to give the –OH (or –ol) the lowest locant, name substituents alphabetically: (i) 2,2,4-trimethylpentan-3-ol, (ii) propane-1,2,3-triol, (iii) 2-ethoxybutane, (iv) 2,6-dimethylphenol, (v) 4-chloro-2,3-dimethylpentan-1-ol.
>
> **(i) $CH_3{-}CH(CH_3){-}CH(OH){-}C(CH_3)_2{-}CH_3$.** Longest chain through the –OH carbon is 5 C (pentan-3-ol). Numbering to give –OH the lowest locant places two methyls at C2 and one at C4:
> $$\Rightarrow 	extbf{2,2,4-trimethylpentan-3-ol}$$
>
> **(ii) $HO{-}CH_2{-}CH(OH){-}CH_2OH$.** A 3-carbon chain with –OH on all three carbons (glycerol):
> $$\Rightarrow 	extbf{propane-1,2,3-triol}$$
>
> **(iii) $H_3C{-}CH_2{-}O{-}CH(CH_3){-}CH_2{-}CH_3$.** This is an ether: the larger group is the butan-2-yl chain, the smaller is ethoxy at C2:
> $$\Rightarrow 	extbf{2-ethoxybutane}$$
>
> **(iv)** A benzene ring with –OH and a –CH$_3$ at each ortho (2 and 6) position:
> $$\Rightarrow 	extbf{2,6-dimethylphenol}$$
> …

Q.Write IUPAC name of the following compounds:

Concept understanding — IUPAC Nomenclature

IUPAC Nomenclature (Organic Compounds)

The Recipe

Worked Example

Why this formula?

IUPAC Nomenclature: Why the Rules Work the Way They Do

1. The Core Principle: The Longest Carbon Chain

2. Numbering: Lowest Locants (The "First Point of Difference" Rule)

3. Alphabetical Order of Substituents

4. Multiple Bonds: The "Lowest Locant" Rule for Alkenes/Alkynes

5. The "Suffix" and "Prefix" System …

Q.Write IUPAC name of the following compounds:

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