Enantiomerically pure 1,3-dioxanes as highly selective NMDA and σ₁ receptor ligands.

We synthesized and investigated the NMDA and σ₁ receptor affinity of enantiomerically pure 2-(2-phenyl-1,3-dioxan-4-yl)ethanamines 17-26. The primary amines (R,R)-18-20 with an axially oriented phenyl moiety in position 2 interacted with high enantioselectivity (eudismic ratios 70-130) and high affinity (K(i)((R,R)-19) = 13 nM) with the PCP binding site of the NMDA receptor. Introduction of an N-benzyl moiety led to potent σ₁ ligands including compound (S,R)-22 (K(i) = 6 nM) with an equatorially oriented phenyl moiety in position 2.