If you're starting from scratch with Doctrine2, I would strongly advise you to come at it the other way around: Define your entities in doctrine, and use the doctrine CLI to generate and update your MySQL schema.
Remember, with Doctrine2, your Entities (which are 'just plain php objects') are first-class citizens. Database schema is just an implementation detail.
Once you get the hang of this workflow, it's incredibly productive. When the need arises, you can pull in the doctrine migrations library, and use it to easily manage schema changes over time.