If you are asking about running a single speaker per channel off of the front channels and 2 speakers per channel off of the rear channels (I am assuming each of the 2 speakers to be run off the rear amp outputs are both 4 Ohm so you're making a 2 Ohm load with them, correct?) then so long as your amp is 2 Ohm stable in stereo mode then you're gold.
The common opinion about this kind of setup notwithstanding the easy answer to your question is Yes. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif