Question

The order of leaving group ability is :
i. $-OAc$ ii. $-OMe$
iii. $-OS{O}_{4}Me$ iv. $-OS{O}_{2}C{F}_3$

• A. $\left(i\right)>\left(ii\right)>\left(iii\right)>\left(iv\right)$
• B. $\left(iv\right)>\left(iii\right)>\left(i\right)>\left(ii\right)$
• C. $\left(iii\right)>\left(ii\right)>\left(i\right)>\left(iv\right)$
• D. $\left(ii\right)>\left(iii\right)>\left(iv\right)>\left(i\right)$

Answer 1

The correct option is B $\left(iv\right)>\left(iii\right)>\left(i\right)>\left(ii\right)$

Weaker the base, better is the leaving group
The decreasing order of acidity is $F_{3}C-S{O}_{3}H>MeS{O}_{3}H>AcOH>MeOH$
The increasing order of basicity is $F_3{C}^{⊝}<MeS{O}_3^{⊝}<Ac{O}^{⊝}<Me{O}^{⊝}$
$\left(iv\right)$ $\left(iii\right)$ $\left(i\right)$ $\left(ii\right)$
The decreaing order of leaving group ability is $\left(iv\right)>\left(iii\right)>\left(i\right)>\left(ii\right)$