One-pot synthesis of protected 1,5- or 3,5-(PP)2-myo-InsP4 (15a/15b) followed by high-pressure hydrogenation to yield enantiopure myo-InsP8 (3 or 4) as octasodium salts. Dotted Box: PAGE analysis of synthetic myo-InsP8 with synthetic standards (5-myo-InsP7, 1-myo-InsP7) and commercial standards (polyphosphate and myo-InsP6). Stained with toluidine blue. BSTFA = N,O-bis(trimethylsilyl) trifluoroacetamide, DBU = 1,8-diazabicyclo[5.4.0]undecene, TFA = trifluoroacetic acid, mCPBA = meta-chloroperbenzoic acid, Bn = benzyl.