C ++ typedef rule syntax

Throughout my life, I cannot find a good explanation of what rules are used to convert a typedef into a C ++ operator. Simple cases that I understand. But consider this from Danny Kalev :

typedef char * pstr;
int mystrcmp(const pstr, const pstr); //wrong!

Then Danny Kalev writes:

The sequence const pstr actually means char * const (a const pointer to char); not const char * (pointer to const char.

I cannot find a rule anywhere to explain why "const pstr" will be converted to "char * const".

Thanks for any help.