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

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

Here is the step-by-step chemical reaction and explanation:

Step 1: Identify the Reactants
The reaction shown in the image involves:
1. Acetone (Propanone): A ketone with the formula ${\mathrm{CH}}_3-\mathrm{CO}-{\mathrm{CH}}_3$.
2. Ethylmagnesium bromide: A Grignard reagent with the formula $C_2{H}_5\mathrm{MgBr}$ (or ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{MgBr}$).

Step 2: Nucleophilic Addition (Grignard Reaction)
In dry ether, the nucleophilic ethyl group $({\mathrm{CH}}_3{\mathrm{CH}}_2{)}^{-}$ from the Grignard reagent attacks the electrophilic carbonyl carbon of acetone. This causes the pi bond of the carbonyl group to break, transferring electron density to the oxygen atom to form an intermediate magnesium halide alkoxide adduct:
$\left({\mathrm{CH}}_3{)}_{2}C\right(\mathrm{OMgBr}){\mathrm{CH}}_2{\mathrm{CH}}_3$

Step 3: Hydrolysis
Subsequent acid hydrolysis $(H_{2}O,H^{+})$ protonates the alkoxide oxygen, converting the adduct into a tertiary alcohol:
$\left({\mathrm{CH}}_3{)}_{2}C\right(\mathrm{OH}){\mathrm{CH}}_2{\mathrm{CH}}_3$

Step 4: Determine the IUPAC Name
Let us find the IUPAC name of the product alcohol:
1. Find the longest carbon chain containing the -OH group: The longest chain starts from one of the methyl carbons on the left, goes through the central carbon, and continues through the ethyl group on the right. This chain contains 4 carbon atoms, which corresponds to the parent alkane butane.
2. Number the chain: Number the chain from the end closer to the hydroxyl $-\mathrm{OH}$ group (from left to right):
  • Carbon-1: $-{\mathrm{CH}}_3$
  • Carbon-2: $-C\left(\mathrm{OH}\right)\left({\mathrm{CH}}_3\right)-$ (contains both the hydroxyl group and a methyl substituent)
  • Carbon-3: $-{\mathrm{CH}}_2-$
  • Carbon-4: $-{\mathrm{CH}}_3$
3. Identify substituents and their positions: There is a methyl substituent at carbon-2, and the hydroxyl group is also at carbon-2.
Combining these gives the IUPAC name: 2-methyl butan-2-ol.