Can I download OS-X 10.6 to a 2006 mac book pro with OS-X 10.5?

I have a 2006 mac book pro 15" with OS-X 10.5 and I wanted to get OS-X 10.6 so then I could download Mountain Lion because you have to have 10.6 or higher to get Mountain Lion. I wanted to Get this because I have an iPhone 4s and it is not compatible with the iTunes on my computer. So then I downloaded the newest iTunes and now iTunes won't even open because it says that my quick time isn't up to date.

So I was just wondering if it is possible to get 10.6 for a mac that already has 10.5 on it and then if it is possible to then get Mountain Lion for the iTunes.

If you could please help that would be awesome.

1: Mountain Lion will not work on a 2006 MacBook Pro.

2: Run Software Update (from the Apple menu top left corner) this will update you to Mac OS X 10.5.8

3: Run Software Update again and it will update iTunes and Quicktime to the latest versions which will work with Mac OS X 10.5.8

4: You will need to buy a copy of Snow Leopard (Mac OS X 10.6) to update from 10.5.8