SQL & PL/SQL

I'm trying to convert from MySQL to Oracle.

I have existing queries in this form:

select date_add(entered,interval 7 day) < now() as check
from user
where id = 1";

I've converted this to:

select (7+entered) < TO_DATE('2009-06-18','RRRR-MM-DD') as check
from user
where id = 1

When I run this, I get this error:

ORA-00923: FROM keyword not found where expected

If I add parens around the select,

select ( (7+entered) < TO_DATE('2009-06-18','RRRR-MM-DD') ) as check
from user
where id = 1

I get ORA-00907: Missing right parenthesis.

Thanks in advance for any assistance.

Regards,
Marty