my homework rule started day 1 of school--- come home, get snack, do the homework! No "if, and, or buts"! when I got replys, desert went bye-bye. more back talk, bed time got moved up. more talking back- yard work got added to their afternoon. Doing the homewrok ASAP meant they might get $ for a snack the next day at school (or at the end of the week).- or extra desert- or something like that.
I once had a 3rd grader who HATED to read. She had to read 20 minutes every night for homework. Finally it came down to me litterally SITTING on her, holding her head to the book as I read. It sounds harsh, but I only had to do it about a week!LOL Then we began to share the reading, till finally she was reading on her own w/ me holding the book.(and I had 3 younger kids to deal w/ too! LOL)
Maybe all it'll take is you sitting at the table w/ him, talking about what he needs to do. Not you doing the work, but talking it out with him, like they do in school. Maybe he misses the interaction of the classmates?? Sometimes it's simple like that.
Good luck :o)
talk to him when he's in a good mood perhaps??