Oracle 11g install problem on Ubuntu
a) Use an OS that is certified for installing and running Oracle Database (Ubuntu is not amongst them). Native or virtual machine, your choice.

or

b) here is an unofficial guide for installing Oracle 11.2 on Ubuntu Linux
https://forums.oracle.com/thread/1117155

I have never tried myself, but several people succeeded installing Oracle 11.2 on Ubuntu with the help of this.