When I went through organic chemistry, I found that memorizing was not very effective. My recommendation is to work through as many sample problems as you can and make sure that you really understand why each reaction is getting those results (i.e. why does it produce products with these stereochems instead of the opposite ones). Also, look for common trends in reactions, such as carbo-cation stabilization to explain why reactions work. That kind of understanding will help you examine problems that you've never seen before and will be far more effective in approaching test material than brute memorization ever will.
