Not sure if this is still useful 3 months later, but:
if you want the Denon to be the source and the Sonos to play the sound then yes.
If you want the Sonos to be the source and use the Denon and other speakers to play the sound, then I would try an optical cable first, something like this: http://www.bestbuy.com/site/dynex-4-digital-optical-audio-cable-black/9543782.p?skuId=9543782
Dynex - 4' Digital Optical Audio Cable - Black
(406)
Dynex - 8' Digital Optical Audio Cable - Black
(477)