You are in a tough spot. I have some ideas for stategy, but they depend on what you want to get out of the situation. Is your goal to leave him in this class and help him learn to meet the behavioral standard as she has set it? Is your goal to leave him in this class and pursuade this teacher to change her techniques so that he is more cooperative? Is your goal for to have the teacher accept a different standard of behavior than she is now? Is your goal to remove him to a class with a more flexible teacher/ teacher who brings out better behaivior/ teacher who keeps him engaged even when he is unable to meet the behavior standard?
I think that the big issue here for you, and what you need to come to terms with first, is what is the nature and cause of his undesirable behavior? This question is going to come up soon, if it has not already, so here goes: is there a possiblity that there is a nuerological basis for his issue? If you go to the principal and make a request to move your son, or you complain about this teacher, the focus will quickly change from her, to your son. You need to know that this will be the case, and be prepared for that conversation. From my experience as an advocate, this is where many relationships become derailed, and quickly, and unforutunatley, the derailment is very difficult to set right once it goes off course in this direction. If you are totally opposed to the idea that there could be a simple, nuerulogical barrier for your son, your school will likely target that, and you, as a difficult parent/child and be less willing to help you resovle this problem creatively. I am not saying that this situation is right, just that it is a reality, and you want to seem like a parent who is working with the school, and not like the one that they feel has caused the issue and thus feel free to ignore, put off, or blame, while they tighten the ropes around your son to show you how wrong you are. That is the situation you want to avoid.
If the converstaion turns to evaluation, or if someone suggests ADHD, know what to do. Once the school suggests a dianosis, they are obligated to evaluate. So decide if you want them to evaluate your son. You may very well, and even if you are generally opposed to this idea, it can work for you in the long run. Behavior that is causing him an issue, or other children an issue in the classroom can be the focus of a behavior plan through an IEP, and this could protect him from the kinds of teacher interventions that you find unacceptable by his present teacher, and would direct exactly what is to take place for your child when he misbehaves, and is legaly required to be only positive intervention strategies and supports, so that may be something you want to have in place.
You may want to know what the results of an educational evaluation will be prior to one that the school suggests, that way, you know what is coming, and will never know less than the school does about your son. You might want to consider getting an opinion from a Neuropsychologist about all of his processing skills and educational functioning, especially since he is reading at such a high level, you will want to see on paper where the highs and lows are in his processing profile so that you know the areas that may be causing him to lose track of his behavior in terms of his intelectual process. For instance, if he is very verbal, very visual, but only average in some output skills like fine motor or visual motor skills, he may misbehave when the classroom expectation calls for him to use skills that he finds more difficult, even if his ablity is average compaired to his peers, compared to his own intelectual functioning, it may seem stupid to him, and it is better to be in trouble for (anything) than it is to feel stupid. A full educational evaluation for your son, will probably give you huge insights into what is going on here, and you can easily argue (via the data) that he is not a "bad" boy, but that there are reasons and strategies that will help him to behave in class. It may not be a diagnosable neurological issue at all, but you should know this before you are face to face with a school evaluator who may interpret the data in a way that you find less acceptable. Just that he is reading at such a high level is probably reason enough for you to seek out a greater, more detailed understanding of his educational profile.
This would be the way I would approach things, if I were advising you as an advocate. First, I would try to get a Neuropsychological evaluation as soon as I could. This may take a while. In the mean time, I would get a calandar, and keep track of every day that your son has a physical complaint, every communication from the teacher, and start saving his work in chronological order. Save notes, emails, etc. You might want to write to last years teacher, and ask her to document the behavior she saw, what inclass interventions she used, and how effective they were, including the progress she saw with your son in his behavior. This is important, if he responded to a particular intervention, you shoud be able to show them, on paper, what was done in class that was successful.
Aproaching your son's teacher is essential. You must do this first, or any discussion with her higher ups will lead you back to her door step, and it will be much more akward. Make an appointment for a parent teacher conference, and treat her with kid gloves. Listen more than you speak, and get an idea of what she really thinks, which you are going to know if you are quiet, and she does the bulk of the talking. You want to ask her questions, and let her fully answer them. First, you want to know what he is doing, and let her get this totally out, even if she is ranting about your son. Bite your tounge, and let her say what she wants to say. Your goal here is to hear how she views it, and him. Then, you want to know what happend just prior to the behavior. She may have no idea, and claim that there is no pattern. Ask what they were doing academically before the behavior, and see if she continues to volunteer that there is no pattern. Then, ask that the behavior be documented according to time of day, educational activity, social interatction, etc, so that you can document that his behavior is global. Go with her suggestion that there is no pattern, and ask her to document that there is no pattern, NOT that you want her to prove that a pattern is there and that you disagree, but go with her suggestion that there is no pattern and agree that you need some documentation that it is like that so that you all can get to the bottom of what is going on. At this point, if you sense resistance from her, assure her that you need this from her for your private evaluator, because you are so concerned about your son, and want to help him.
When you go home from this meeting, write out what you said to the teacher, and send her a thank you email that details what she said she was seeing in the classroom, and what she wanted to do to help him, and what she was going to do to document the "non pattern." Note at the bottom that you wanted to be sure you understood what was going to happen, and ask her to confirm, add that you are willing to do anything else that she requests. Each time you speak to the teacher, you should follow up with a confirmation of what you discussed in an email, and keep a copy.
Dual exeptionality is very common, but being very bright also can create needs that are not nuerological issues. You need to know where your son lies, because my guess is that he has one or the other issues going on, and he is not a "bad boy" at all. Your goal should be to make sure that he gets help so that he does not start thinking of himself in this way, and does not live down to the bad behavoir expectation. It is a myth that very smart children are smart enough to know how to fix these things themselves, they are still children, and my experience is that teachers often have this misconception about very smart children that their behaviors are deliberate choices and that they can control them because they are so smart. It seems to be kind of "duh" to me, but if kids are very smart, they would have fixed it themselves already if they could, and they need some kind of help (based on data) to do so. I also think it is kind of "duh" that kids your son's age all really want to comply and would surely please every adult around them if they could. I really think that adults assist kids into becoming chronic classroom behavior issues by not recognizing when a child needs help and blaming them for what they cannot control by backing them into a corner so that they would rather "choose" to be in trouble than to admit that they cant figure out how to stop getting into trouble. They know they are smart, and it does not compute for them that they can't just fix this either, so it is much more palitable to a 2nd grader to say "I meant to do that...so!" than it is to say, I have no idea why I did that...
I hope this helps.
M.