Note when I follow the oradoc example (bolded large font below):

DELETE Statements

You can delete from a join view provided there is one and only one key-preserved table in the join. The key-preserved table can be repeated in the FROM clause.

The following DELETE statement works on the emp_dept view:

DELETE FROM emp_dept WHERE ename = 'SMITH';

This DELETE statement on the emp_dept view is legal because it can be translated to aDELETE operation on the base emp table, and because the emp table is the only key-preserved table in the join.

In the following view, a DELETE operation is permitted, because although there are two key-preserved tables, they are the same table. That is, the key-preserved table is repeated. In this case, the delete statement operates on the first table in the FROM list (e1, in this example):

     CREATE VIEW emp_emp

AS SELECT e1.ename, e2.empno, e2.deptno

     FROM emp e1, emp e2

     WHERE e1.empno = e2.empno;

I tried the above and it worked great. here is my version of how I tried it

CREATE VIEW emp_emp

AS SELECT e1.last_name, e2.employee_id, e2.department_id

FROM employees2 e1, employees e2

WHERE e1.employee_id = e2.employee_id; /* (employees table in HR schema)*/

delete from emp_emp where employee_id between 100 and 190;

then I tried my own and not so much luck. Note in the below example I am using the employees table from HR schema

In any case here it is:

CREATE VIEW Emp_test AS

    SELECT e1.last_name last_name , e1.employee_id, e2.department_id

       FROM Employees2 e1, Employees2 e2

            WHERE e1.employee_id = e2.employee_id;

            delete from emp_test where employee_id = 100;

Note there is one key preserved table here, my underlying employees2 table.

Error: ORA-01752: cannot delete from view without exactly one key-preserved table

01752. 00000 -  "cannot delete from view without exactly one key-preserved table"

*Cause:    The deleted table had

           - no key-preserved tables,

           - more than one key-preserved table, or

           - the key-preserved table was an unmerged view.

*Action:   Redefine the view or delete it from the underlying base tables.

In this case it is just repeated and as the doc says:

DELETE Statements

You can delete from a join view provided there is one and only one key-preserved table in the join. The key-preserved table can be repeated in the FROM clause.

http://docs.oracle.com/database/121/ADMIN/views.htm#ADMIN11782

What am I missing in my script...? I tried a few variations all no luck, I can't figure out what's wrong.

In the doc if you ctrl+f the word 'repeat' it will make finding repeated key preserved topics much easier (that's the only time the word repeat is used)