loading GRUB into fresh partition structure

      I have recently decided to push the limits of all I understand about Linux, so I completely wiped all my partition structures to start fresh. I created a 512MiB primary partition, flagged it as bootable, and am trying to get GRUB2 to install on this partition so i can chainload the MBR through about 10 or so various Linux distros. The rest of the drive is still unallocated space, and not of concern here, but I need an effective command to get grub to install into this partition. I found a command that I believe may be able to be effective

grub-install --root-directory=/boot /dev/sdb1

but get the following:

unshare failed: Operation not permitted
grub-probe: error: failed to get canonical path of /cow.
mkdir: cannot create directory ‘/boot/boot’: Permission denied

I can obviously use 'sudo' for the permission issues, but that is the extent of my solution. I have been google-ing and trying things for at least ten hours now, and have reached the end of my patients. Having no native OS on the system, it is currently running from Linux Mint 15 on a USB startup disk. Any ideas how i can get this to install the MBR so i can just use a grub menu and then install all my OS's from there.
And yes, I know that VM's are a better and safer option, but this is an excersize of curiosity as much as anything.