No.   Storage Spaces uses a block based method for storing the data, while StableBit DrivePool uses a file based method.  So there is no direct way to convert.  You'd have to remove the drives from the Storage Spaces array (which is destructive, eg, wipes the data), and then add the disks to a pool.     However, you can add a Storage Spaces array to a pool, and use it directly that way, until you have enough storage to break the Storage Spaces array and re-add those disks.