Epimeric C-glycoside based polyphosphates, α- and β-d-glucopyranosylmethanol 3,4,1'-trisphosphates (8 and 9) were prepared from d-glucose. The key intermediate, allyl 2,6-di-O-benzyl-α-d-glucopyranoside, was prepared in five steps (67% yield) from allyl α-d-glucopyranoside without the need for chromatography. Compounds 8 and 9 were shown to be full agonists at the Ins(1,4,5)P 3 receptors of permeabilised hepatocytes, but with markedly different potencies. Such C-glycoside analogues are worthy of further development as Ins(1,4,5)P 3 receptor ligands.