  We predict a discriminatory interaction between a chiral molecule and an
achiral molecule which is mediated by a chiral body. To achieve this, we
generalize the van der Waals interaction potential between two ground-state
molecules with electric, magnetic and chiral response to non-trivial
environments. The force is evaluated using second-order perturbation theory
with an effective Hamiltonian. Chiral media enhance or reduce the free
interaction via many-body interactions, making it possible to measure the
chiral contributions to the van der Waals force with current technology. The
van der Waals interaction is discriminatory with respect to enantiomers of
different handedness and could be used to separate enantiomers. We also suggest
a specific geometric configuration where the electric contribution to the van
der Waals interaction is zero, making the chiral component the dominant effect.
