Cramming is a horrible idea for any class that you will have to draw upon in the future. With regard to O-Chem 2, you'll need some of the information for the mcat. Whenever you cram anything, you store the information in the short term memory loss category so have fun re-learning the content for when the mcat roles around. The key with organic chemistry is pattern recognition and actually making sure that you know/understand the material. For instance, look over a mechanism and try to make sense of what is happening. You know that carbonyl bonds are highly polar, and that the oxygen is negatively charged while the carbon is positively charged. First off, ask yourself why the oxygen is negative and why the carbon is positive. If you don't know, then look it up or ask. Use this strategy for every step in a mechanism. Also, do not just look over a mechanism; close the book and try to re-write the mechanism according to what makes sense rather than what comes off from memory. Practice is important to a certain extent but a firm grasp of the concepts will limit the amount of practice you need to apply these concepts.
The class is not really that bad; just keep a consistent study schedule, keep reviewing, keep truckin at the material until you understand what the hell is going on, do practice problems in areas that you feel you need additional practice in (no point in practicing the stuff you already are very confident in unless that somehow builds your self-esteem that you are getting work done which you actually are not getting any work done because you're just going over crap that you already know really well). Lastly, don't look at the content as all memorization. The information is actually pretty interesting, especially in the lab. If you can find a way to convince yourself that the knowledge your gaining is useful and applicable, then it makes studying a hell of a lot easier. Good luck buster