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 (Ki((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 (Ki = 6 nM) with an equatorially oriented phenyl moiety in position 2.