What is the IUPAC name of the organic compound formed in the following chemical reaction ?

The correct answer is 2-methyl butan-2-ol.

Step-by-Step Explanation:

1. Identify the Reactants:
- Acetone (Propan-2-one): A ketone with the chemical structure ${\text{CH}}_3-\text{CO}-{\text{CH}}_3$ containing a highly polar carbonyl group (C=O).
- Ethylmagnesium bromide (${\text{C}}_2{\text{H}}_5\text{MgBr}$): A Grignard reagent that serves as a source of the nucleophilic ethyl group (${\text{C}}_2{\text{H}}_5^{-}$).

2. Step 1: Nucleophilic Addition of Grignard Reagent:
The nucleophilic ethyl group (${\text{C}}_2{\text{H}}_5^{-}$) attacks the electrophilic carbonyl carbon of acetone in dry ether. The electron pair from the C=O double bond shifts to the oxygen atom, forming a magnesium salt intermediate:
${\left({\text{CH}}_3\right)}_2\text{C}=\text{O}+{\text{C}}_2{\text{H}}_5\text{MgBr}\to {\left({\text{CH}}_3\right)}_2\text{C}\left(\text{OMgBr}\right)\left({\text{C}}_2{\text{H}}_5\right)$

3. Step 2: Acid Hydrolysis:
Subsequent protonation/hydrolysis of the alkoxide intermediate with water in an acidic medium (${\text{H}}_2\text{O}/{\text{H}}^{+}$) yields a tertiary alcohol:
${\left({\text{CH}}_3\right)}_2\text{C}\left(\text{OMgBr}\right)\left({\text{C}}_2{\text{H}}_5\right)+{\text{H}}_2\text{O}\to {\left({\text{CH}}_3\right)}_2\text{C}\left(\text{OH}\right)\left({\text{C}}_2{\text{H}}_5\right)+\text{Mg}\left(\text{OH}\right)\text{Br}$

4. IUPAC Nomenclature of the Product:
- The structure of the resulting alcohol is:
${\text{CH}}_3-{\text{CH}}_2-\text{C}\left(\text{OH}\right){\left({\text{CH}}_3\right)}_2$
- The longest continuous carbon chain containing the hydroxyl (-OH) group has 4 carbon atoms, which corresponds to butane.
- Numbering the chain from the right side gives the lowest locants to the substituents:
  • C1: $-{\text{CH}}_3$ (terminal right)
  • C2: Carbon bonded to both the $-\text{OH}$ group and a methyl ($-{\text{CH}}_3$) substituent
  • C3: $-{\text{CH}}_2-$
  • C4: $-{\text{CH}}_3$ (terminal left)
- Combining these substituent locations, we have a methyl group at carbon-2 and the alcohol group at carbon-2.
- Therefore, the IUPAC name is 2-methyl butan-2-ol.