prepositions - Is the structure "X, whom I've had the pleasure of being the mentor of" proper?

John is the mentor of Anna. John introduces Anna as:

1. "Anna, whom I've had the pleasure of being the mentor of".

Would the following be more correct?

2. "Anna, of whom I've had the pleasure of being the mentor"

Answer

The second way is only "more correct" if you don't like ending phrases like that with prepositions. Many people might think it sounds weirdly formal.