Union in PostgreSQL

I want to achieve the following behaviour NULL AS (Oracle database):

CREATE OR REPLACE VIEW cuentaahorroview AS
    SELECT IBAN as CCC, Interes, Ultimo_devengo
        FROM De_Ahorro
    UNION
    SELECT CCC, TIPOINTERES as Interes, null as Ultimo_devengo
        FROM CUENTAAHORRO@SCHEMA2BD2;

in a PostgreSQL database:

CREATE VIEW EditorialView AS
    SELECT * 
        FROM dblink('hostaddr=127.0.0.1 port=5432 dbname=bdp3e1 user=postgres password=1234', 'SELECT * FROM Editorial') 
        AS t1(nombre VARCHAR(100), CIF integer, ubicacion VARCHAR(50))
    UNION
    SELECT *
        FROM dblink('hostaddr=127.0.0.1 port=5432 dbname=bdp3e2 user=postgres password=1234', 'SELECT * FROM Editorial')
        AS t2(nombre VARCHAR(100), CIF integer, NULL);

so as the union to work. How can I do it?

This is the error I'm getting:

psql:PR3_Vistas.sql:10: ERROR:  syntax error at or near "NULL"
LINE 8:   AS t2(nombre VARCHAR(100), CIF integer, NULL);