Hi L.,
When my son went through this at the same age (well over 20 years ago)I was very surprised, because I had no problems training our daughters.
He would go as far as hiding in his closet and squat in the corner of it with the door closed in order to avoid using the potty.
Our doctor told us this is very common with little boys. Some of them are just shy about the potty. He said to keep our cool. Praise and reward him for success, but don't punish failure.
He's just not ready yet. Some little boys will be as old as 3 or 4 before they start to "get it". It's not that they can't, but it really upsets them.
It doesn't seem like it now, but he WILL outgrow this.
My son is now 24 years old, and I am pretty sure he has not pottied in his pants in a closet for a number of years. :o)
Seriously, he did get trained well before kindergarten. When he is ready, your consistancy and calm patience will pay off and it will seem as if he gets trained over night.
I wish you well. :o)
B.