> Can anyone explain how to find out which atom is the stereocenter?
>
>
Sure! A stereocenter is the central point around which the arrangements
of atoms in space make a molecule chiral. In the case of tetrahedral
structures, or sp3 bonds, this would be ANY ATOM TO WHICH FOUR *DIFFERENT*
GROUPS ARE ATTACHED. In the case of 2-butanol (used this morning in class)
the C-2 atom is the stereocenter because it is attached to a hydroxyl
group (OH) a hydrogen, a methyl group, and an ethyl group. This definition
works for any tetrahedral arrangements of atoms.
-Leslie