At the moment I don't know about the existence of any CD-i emulator with open source code. If any source code of any CD-i emulator is released in the future, it could be ported to Xbox (allways keeping in mind that Xbox will have a hard time to emulate it, as CD-i is in the same generation as consoles like the 3d0 or the Saturn, whose emulation is not 100%). But nowadays it seems that we have no open CD-i emulator to port
As far as the CD-i Zelda games is related, be warned that they are not similar to the other Zeldas. Maybe you can see the AVGN episode related to the CD-i, or any Youtube videos about CD-i playing Zelda, and you will see that they are not "typical" Zelda games. I am not saying that they were bad... but if you are expecting classical Zelda games, they are not that kind...