Answer:
1. HOCH₂CH₂OH/H₂SO₄
2. CH₃CH₂MgBr (2 eq)
3. H₃O⁺
Step-by-step explanation:
Assume the conversion is the one in the first Figure.
You want to convert the ester to a 3° alcohol.
However, you must first protect the ketone from reacting.
(i) React the compound with ethylene glycol and sulfuric acid. The ketone is converted to a cyclic acetal.
(ii). Add two molar equivalents of ethylmagnesium bromide. Two moles of the Grignard reagent convert the ester into the magnesium salt of a 3° alcohol.
(iii) Aqueous acid removes the protecting group and converts the salt to an alcohol.
The first set of options is wrong. LiAlH₄ reduces the ester to a 1° alcohol.
The second set of options is wrong. Concentrated sulfuric acid won't do anything. Aqueous sulfuric acid will hydrolyze the ester to methanol and a carboxylic acid. Ethanol will convert the acid to an ethyl ester, but aqueous acid will hydrolyze it again.