No.
Unless you split up the stereo signal with a splitter (twice) but thats stupid.
It would work as I said with those cables but it'd be pointless, not sure why I mentioned it actually. The speaker connections are like those for pc 5.1, which sometimes come with a a connector like this:
If you were going to use the adapter above, don't bother with an optical cable though, it would make sense to get a standard 3.5mm to 2 phono cable. You'll never get proper 5.1 either way.
Unless you buy a 5.1 amp and some 5.1 speakers. Plenty of stuff on avforums usually in the classifieds or on eBay that'll be good starter kit of you don't want to spend a lot.