To synthesise 1.0 mole of 2-methylpropan-2-ol from Ethylethanoate ____ equivalents of reagent will be required. (Integer value)
Answer: 2
Solution
A Grignard reagent attacks the ester carbonyl and the tetrahedral intermediate expels ethoxide, which gives a ketone, here propanone from ethyl ethanoate. A ketone is more electrophilic than the ester it came from, so it is attacked at once by a second molecule of the reagent, and the alkoxide produced is protonated on work-up:
Two of the three methyl groups on the carbinol carbon of the product come from the reagent and only one from the ester, so 1.0 mole of 2-methylpropan-2-ol requires 2 equivalents of .
Two of the three methyl groups on the carbinol carbon of the product come from the reagent and only one from the ester, so 1.0 mole of 2-methylpropan-2-ol requires 2 equivalents of .
JEE Main · 2021 · 20 Jul 2021 · Shift 1 · Integer answer