Is using reference to pointer that was casted with reinterpret_cast undefined behavior?

Question

Is the following code UB?

int   i  = 5;
void *p  = &i;

int* &r  = reinterpret_cast<int* &>(p);
int*  p2 = r;

Please note I do not dereference pointer.

Answer 1

Yes, it is UB.

reinterpret_cast<int* &>(p);

is equivalent to

*reinterpret_cast<int**>(&p);

reinterpret_cast of void** to int** is allowed, but the implicit dereference is UB because the type of data (void*) and the type it is being accessed as (int*) are not similar.