About this age you could expect baby to drop to one nap but do be guided by tired signs. If you think he is ready, offer an early lunch around 11am and try to have him down by 12noon for a couple of hours. You might also want to get in with an early dinner because he will be getting overtired by the end of the day and will fall asleep in the plate. What you must avoid at all costs is napping at 4 or 5pm.
It's Time to Sleep