Herein we report an efficient solid-phase synthesis of some N-1-alkyl-substituted analogs of cyclic inosine-diphosphate-ribose (cIDPR), a mimic of cyclic ADP-ribose (cADPR) which has been described as an agonist of the cADPR/Ca(2+) signalling system. The proposed synthetic strategy uses a polystyrene support bearing inosine by a 2',3'-acetal linkage which is converted into several N-1-alkylinosine-bis-phosphate derivatives which in turn were cyclized by a solid-phase pyrophosphate bond formation.