「〜でない。」, which isn't particularly common as a sentence-ender, does occasionally get used. I get the feeling it is pretty curt; I often see it with 「〜べきでない。」 or 「ただし、〜は、この限りでない。」 or 「〜は明らかでない。」, etc. ...
I'm studying for the N1. And there are several not so often used structures that you really need to know the minute differences between. One of these is the uses of 至る. As far as I know, these are ...