Two routes from D-glucose to chiral, ring-contracted analogs of the second messenger D-myo-inositol 1,4,5-trisphosphate are described. Methyl α-D-glucopyranoside was converted by an improved procedure into methyl 4,6-O-(p-methoxybenzylidene)-α-D-glucopyranoside (6) and thence into methyl 2-O-benzyl-3,4-bis-O-(p-methoxybenzyl)-α-D-gluco-hexodialdopyranoside (1,5) (14) in four steps. In the first ring-contraction method 14 was converted into methyl 2-O-benzyl-6,7-dideoxy-3,4-bis-O-(p-methoxybenzyl)-α-D-gluco-hept-6-e nopyranoside (1,5) (15), which on sequential treatment with Cp2Zr(n-Bu)2 followed by BF3·Et2O afforded a mixture of (1R,2S,3S,4R,5S)-3-(benzyloxy)-4-hydroxy-1,2-bis[(p-methoxybenzyl)oxy] -5-vinylcyclopentane (16) and its 4S,5R diastereoisomer 17. Removal of the p-methoxybenzyl groups of 16 and subsequent phosphorylation and deprotection afforded the first target compound, (1R,2R,3S,4R,5S)-3-hydroxy-1,2,4-tris(phosphonooxy)-5-vinylcyclopentan e (3). In the second route, intermediate 14 was subjected to SmI2-mediated ring contraction to give (1R,2S,3S,4R,5S)-3-(benzyloxy)-4-hydroxy-5-(hydroxymethyl)-1,2-bis[(p- methoxybenzyl)oxy]cyclopentane (20). Benzylation of 20 provided (1R,2S,3S,4R,5S)-3-(benzyloxy)-6-[(benzyloxy)methyl]-4-hydroxy-1,2-bis [(p-methoxybenzyl)oxy]cyclopentane (22) and (1R,2S,3S,4R,5S)-3,4-bis(benzyloxy)-5-(hydroxymethyl)-1,2-bis[(p-metho xybenzyl)oxy]cyclopentane (21), which were elaborated to the target trisphosphates (1R,2R,3S,4R,5S)-3-hydroxy-5-(hydroxymethyl)-1,2,4-tris(phosphonooxy)c yclopentane (4) and (1R,2S,3R,4R,5S)-1,2-dihydroxy-3,4-bis(phosphonooxy)-5-[(phosphonooxy) methyl]cyclopentane (5), respectively. Both 3 and 4 mobilized intracellular Ca2+, but 4 was only a few fold less potent than D-myo-inositol 1,4,5-trisphosphate, demonstrating that effective mimics can be designed that do not bear a six-membered ring.