Hmmm....Good question....short of a custom adapter, is your hub set up to use the standard ISO mounting for a disc brake?....If so, the sprocket can be mounted in place of the disc.....I was experimenting with this as an alternative to the HD 9 hole mounting system because some people were complaining of spoke breakage and also, by mounting the sprocket where the brake disc would normally go it would make for a very accurate /
precise mount (no more run out or wobble)....Of course the disc normally does sit a little further outboard and this may cause a minor alignment issue on some bikes (not all but possibly some)....Another benefit of a direct mount would also be that the sprocket could be changed out a lot more quickly.....I realize that Grubee makes / imports a hub for such a situation (direct mount of a sprocket to the hub) but I believe that their hub is more expensive than many disc brake hubs and is also not as good in quality form posts I have read. Hope this helps.
Andrew