Fourteen 4-alkyl-3-cyano-caged bicyclic-phosphates were synthesized from 2-alkyl-2-hy- droxymethyl-1,3-propanediols via protection of the two hydroxyl groups, oxidation of the other hydroxyl group with PCC, introduction of the CN group, deprotection and cyclization with POCl3 or PSCl3. All target compounds were confirmed by 1H NMR, MS spectra and elemental analysis. In addition, the 14 compounds were examined for their inhibition of [3H]EBOB [4’-ethynyl-4-n-propylbicycloorthobenzoate] binding to housefly and rat GABA receptors and the results show that some of these compounds have inhibiting activity and selectivity between the rat and housefly GABA receptors at 10－5 mol/L.

Key words: GABA receptor, radioligand receptor binding assay, bioactivity, caged bicyclic-phosphate