Question

How many $HI$ can react with following compound?

• A. $2$
• B. $3$
• C. $5$
• D. $6$

Answer 1

The correct option is A $2$

As we can see, the reaction with $HI$ involves an $S_{N}2$ pathway with a fairly large nucleophile $I^{-}$. After two steps, the third $-OC{H}_3$ group becomes sterically restricted and cannot participate in another $S_{N}2$ substitution.
Thus,Option A is the correct answer.