(αS)?-α-?Methoxy-?N-?(tetrahydro2-?oxo-?3-?thienyl)?benzeneacetamide is an intermediate in the synthesis of D-Homocysteine Thiolactone Hydrochloride (H591320), which is a moderate mGlu receptor agonist and thus suggests that moderate hyperhomocysteinemia may be associated with several diseases including coronoary artery, Alzheimer’s disease and schizophrenia.