Question

A partially racemised (+)-$2$-bromo-octane ($2^{o}RX$) on reaction with aq. $NaOH$ in acetone gives an alcohol with $80$% inversion and $20$% racemisation. What condition the reaction would follow $S{N}^1$ mechanism?

• A. Low concentration of $\stackrel{⊝}{O}H$
• B. High concentration of $\stackrel{⊝}{O}H$
• C. Low concentration of $2^{o}RX$
• D. High concentration of $2^{o}RX$

Answer 1

The correct option is A Low concentration of $\stackrel{⊝}{O}H$

$S_{N}1$ is favored when the generating carbocation is stable.
Hence, the carbocation will be more stable in low concentration of $\left[\stackrel{⊝}{O}H\right]$ i.e more concentration of water which provides hydration stability by accommodating around the carbocation.