ive researched this myself. very few schools offer "deferred admission" like i've seen one so far up and down the east coast - but i dont know if you need a better reason than havent completed prereqs, schools mostly want to see if you can pass those classes. on the other hand i have seen a few schools where if you just need a course or two of the liberal arts requirements for the school they'll let you complete them during your first semester but that seems like a pretty rough semester if you ask me. better off just putting off applying for a year.