T-SQL - CASE Statement

I need to execute a simple Case Statement.  Strangely, if I include a comparison operator I receive an error message showing a syntax error (Message 102, Level 15).  But the same statement without the operator works jsut fine.

Works:

Select LastName, Group =

Case Age

When 15 Then '1'

When 18 Then '2'

Else '20'

From tblAgeGroup

End

Does Not Work:

Select LastName, Group =

Case Age

When <15 Then '1'

When <18 Then '2'

Else '20'

From tblAgeGroup

End

Also, I noticed that this does not work in any other combination of the "When.." clause.

Any help is appreciated.

Thanks