Question

When phenol is treated with $D_2SO_4/D_2O$, some of the hydrogens get exchanged. The final product in this exchange reaction is

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

Answer 2

In acidic medium, phenol exists in following resonating structures.

Since, $o / p$ positions are electron rich sites, so electrophile will attack on these site, i.e., hydrogen of these sites get exchanged by $D$ (deuterium). Hence, the final product of the