There is very little available on the net about PDF to XML, and usually its too hard to find some good way to convert the PDF to the XML. Normally you can find any of the software that can convert any of the format into the PDF but from PDF into XML, you will have to search a lot on net. I ve search and I tried most of the result I got in Google for pdf to xml, and among them I found one resource to be worth read and use. And her it is.http.//discerning.com/hacks/docutils/pdf2xml/readme.html There are following stuff given in the above link if you check.There are several third-party commercial tools such as these that convert PDF to various XML vocabularies. See also their online service at pdftextonline.com .There are other commercial tools that go from some XML vocabulary to PDF. I hope these resources will be helpful for you.
And if you have more ideas or tips, I'll be happy to see how in comments here.