How to convert between int * and enum *?

From some C legacy code I get a number of constants as int *. In the C++ part, I have an enum of underlying type int. Conversion between the enum and int on a single value basis works. However, conversion between int * and enum * is not possible. See code example below.

Why is that and how would I convert a pointer to some int values to a pointer to int enums and vice versa? I kind of expect it to work since the single value conversions work and the underlying types are the same. I read about What happens if you static_cast invalid value to enum class? but could not determine if potentially invalid values play a role here.

int i = 3;
enum E : int;
E e;

e = static_cast<E>(i);   // ok
i = static_cast<int>(e); // ok

int *j;
E * f;

j = static_cast<int *>(&i); // ok
f = static_cast<E *>(&i);   // 'static_cast': cannot convert from 'int *' to 'E *'
j = static_cast<int *>(&e); // 'static_cast': cannot convert from 'E *' to 'int *'