Which of the following sets of reactants may be used to prepare `2`-methylbutan-`2-ol`?

Options

A. Propanal and isopropylmagnesium bromide
B. Butanone and methylmagnesium iodide
C. Propanone and ethylmagnesium iodide
D. Either of the above two

Answer

D

Explanation

It is tertiary alcohol , to make it we can use a Grignard reagent and a ketone. There are two choices : we may consider the molecuels to be put together either `(a)` between `C-1` and `C-2`.
`CH_(3)CH_(2)-underset(O)underset(||)overset(CH_(3))overset(|)(C) + CH_(3) - MgI underset((2)NH_(4)Cl//H_(2)O)overset((1)Et_(2)O) rarr `
`CH_(3)CH_(2)-underset(OH)underset(|)overset(CH_(3))overset(|)(C)-CH_(3)`
or `(b)` betwen `C -2` and `C-3`.
`CH_(3)CH_(2)MgI + underset(O)underset(||)overset(CH_(3))overset(|)(C)-CH_(3) underset((2)NH_(4)Cl//H_(2)O)overset((1)Et_(2)O)rarr`
`CH_(3)CH_(2)-underset(OH)underset(|)overset(CH_(3))overset(|)(C)-CH_(3)`