Transferring from UA to SQ??

I am flying ORD-SIN, upgraded to C, with the usual arrival at midnite. ;)

At 10am that morning, I'm outbound on SQ in Biz.

My question: Can I leave airside, retrieve checked luggage, and RE-CHECK them on SQ at that hour in order to get back airside?? I'll obviously need to get BP's as well.

My plan then would be to head for the transit hotel or the SKL. I've never had to do this on my prior 1000 flights into SIN. :D

Thanks! Dave