what ubuntu is compatible with autocad 2009

AutoCAD 2009 is only available for Windows and Mac OS X. In Ubuntu, some Windows programs can be run with Wine (http://winehq.org). While some older versions of AutoCAD are likely to work in Ubuntu this way, AutoCAD 2009 is very unlikely to work (http://appdb.winehq.org/objectManager.php?sClass=application&iId=86).

If you want to run Ubuntu, and want to run AutoCAD while in Ubuntu, then you could potentially run it inside a virtual machine running Windows. Software like VirtualBox and VMware enables you to do this. (But you still have to have Windows, and AutoCAD, in this case. If you run windows software with Wine, you need the Windows software, but you do not need to have a copy of Windows itself.)

If your goal is just to run computer-aided design software in Ubuntu, but not necessarily AutoCAD, then there are a number of CAD programs that run on Ubuntu and other Linux-based operating systems. Some of them are listed at https://help.ubuntu.com/community/UbuntuEngineering (along with other non-CAD engineering programs), and you can find information on others by searching the web.