Amazing professor but hard at the same time. Be expected to memorize over 100 reactions and know the mechanisms for about half of them and plus know NMR.
Here's the deal with the exams:
Midterm 1: Average 50/100
Midterm 2: Average 38/100
3 Quizzes: Averages around 21/30
So expect low averages, but if you study and go to lecture (where he gives out hints for the exam), you'll be fine and manage and A- or even an A. He even has 15 points extra credit on each exam and 5 points on each quiz, and 30 points on the final! That's a s*** load of extra credit. If you keep up with the material and study, you'll manage a good grade and get out of class knowing O-chem and NMR like the back of your hand. Highly recommended teacher!

Great professor.
One of the few professors in UCLA who takes his lectures seriously: no wry jokes, adequate material in each lecture, fluent, organized. He does bombard students with a lot of information per lecture, but all is clearly explained. Gives much extra credit to the class (though i never earn them) Exams are challenging though, but doable as long as you really really really really understand the material (btw an exam is supposed to distinguish able students from others rite). I got an A- and thinks the hard work required worthy...when you turn around after the intriguing final you'll find you've digested 70% of the textbook, and that's a great achievement...
If you really want to learn Org Chem take him
Those who take the class just for getting a good grade without much understanding better avoid him.

He's one of the most concerned and approachable professors I've had so far. Even though the material was difficult in itself, he did a good job of teaching it. I would highly recommend him.

Dr. Cantrill is a very hard professor. However, he is very concerned about his students and he is very nice. He would really go out of his way for his students. With that said, HE IS VERY DEMANDING! He wants you to know all the mechanisms and he loves synthesis problems (which are the hardest in organic chemistry). His tests are extremely long but doable if you know everything. They are from the lectures only, so don't waste time doing all the problems in the book. He may ask you anything including things that he only mentioned slightly once but afterall, he says he did mention. One good thing is that the average on the exams are very low (40s and 50s), and so there is a big curve! Also, you learn a lot from that class and i know that sounded very nerdy. I think he's even a better professor that hardingers because he is more conceptual...
he gives breaks every once in a while, like a shorter class before thanksgiving and he gave candy out on holloween... so overall, i would recommend taking 30 series with him and dont be intimidated by his difficulty ratings...

If u want a bad chemistry teacher, this is the class. He teaches directly from the book, and the book alone. Which in some cases can be a good thing, but the book SUCKS, and he takes his tests from lalala land. Just make sure you KNOW the lecture notes, but DO all the book problems if you want a semi-chance of passing. Most important KNOW DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM DEUTERIUM