Question

For the sequence of reactions A sequence is A. A) 2-butanone C2H5MgI ⟶ B H2O/H+ ⟶ ter-pentyl alcohol

Answer 1

3-methylpentan-3-ol

Answer 2

2-butanone (CH$_3$COCH$_2$CH$_3$) reacts with ethylmagnesium iodide (C$_2$H$_5$MgI) through nucleophilic addition of the ethyl group to the carbonyl carbon, forming a magnesium alkoxide intermediate (B). This intermediate is CH$_3$-C(O-MgI)(CH$_2$CH$_3$)-CH$_2$CH$_3$. Subsequent acidic hydrolysis of the alkoxide intermediate B yields the final alcohol product. The structure of the final alcohol is CH$_3$-C(OH)(CH$_2$CH$_3$)-CH$_2$CH$_3$, which is named 3-methylpentan-3-ol according to IUPAC nomenclature. This alcohol is a tertiary alcohol with 6 carbon atoms. The product name stated in the question, ter-pentyl alcohol (2-methylbutan-2-ol), refers to a 5-carbon tertiary alcohol and is inconsistent with the reactants provided. Based on the given reactants and reaction steps, the product formed is 3-methylpentan-3-ol.