How to set order by clause for this query.

create table mstsubs (subjects varchar(200))
insert into mstsubs(subjects) values('aaan')
insert into mstsubs(subjects) values('baan')
insert into mstsubs(subjects) values('caan')

The output should be
select
ALL
aaan
baan
caan
I am using the following query but not working out.

select subjects
from(select 'Select' as subjects union select subjects from mstsubs
union select 'All' as subjects union select subjects from mstsubs)x
order by case
when subjects = 'Select' then 0
when subjects='ALL' THEN 1
END