Conservative chemical modifications of the core structure of the lead spipethiane (1) afforded novel potentσ1ligands. σ1 affinity and σ1/σ2 selectivity proved to be favored by the introduction of polar functions (oxygen atom or carbonyl group) in position 3 or 4 (4−6) or by the elongation of the distance between the two hydrophobic portions of the molecule with the simultaneous presence of a carbonyl