I would like to know what would be the passive of "The Book reads interesting".
Welcome to Using English.
Your original sentence is not grammatical.
The book is interesting to read -- this is grammatical. However, it cannot be made into the passive, because there is no direct object.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.