The molecule given below is a substituted cubane.
a) How many stereoisomers exist for this molecule?
b) How many pairs of enantiomers are possible?
How do I calculate the number of stereoisomers? Since each carbon is linked to four different groups, can I claim that all are chiral and, therefore, $2^8$ stereoisomers are possible?
If that is true, since there is no element of symmetry, can I say that $2^4$ enantiomeric pairs exist?
Edit: Looking at the comments clears things up but brings forth another question. If, say, iodine was present at any other position that would not lead to a tetrahedron, what would happen?