Well you probably want
- oldpage1 redirect to newpage1
- oldpage2 redirect to newpage2
Not sure if you delete a folder it would do some scientific redirection above. Depending on ho many pages you have you probably need delete them one by one supplying where a deleted page must be redirected to.
if there are too many pages there are different solutions like IIS rewriting rules, there you can regular expressions or you can use API and create aliases for new pages (i.e. this is what happens during delete process if you are redirecting to a new page)