DS just started kindergarten.
I give my kids 30-60 minutes before i make them start their homework. They have a snack and watch a little TV or play outside before its to late. Then they come in and sit at the counter while i make dinner, this keeps them close in case they need help and so i can make sure they are not goofing off.
I'm sorry you're having issues with him not wanting to do homework, that's tough but I'm sure once he's been doing this for awhile it'll become so routine to him that he wont put up such a fuss.
Here our policy is they get off the bus, get a snack, hang out for a bit and then start the homework. Their homework must be done by the time we eat dinner. We have a lot of things in the evening and theres no way I could let them wait until evening to get on it.
Good luck! Hopefully it'll get easier!!