Is there any reason you wouldn't want to do this?
EDIT: More info
I have a website that was built in HTML/CSS and over the years, it's been modified, added to and hacked at to the point where the code is kind of a mess. I'd like to redesign the site using a structured CMS but I want the base HTML/CSS to be well coded and optimized. That's why I'm thinking of building a site using the Bootstrap framework and then rebuilding it in Craft. I realize this seems redundant but I'm not good enough with CSS to just build it from the scratch in Craft. I'm more of the cut and paste kind.
The reason I'm considering Craft is because I like the idea of defining fields and sections I can reuse. I built the site 90% through using ModX, it looked good but the back end and the way it presents Template Variables is not very friendly. I like Craft's approach a lot more.