A stereoselective and efficient totalsynthesis of opticallyactive tetrodotoxin (TTX) is described. A polyfunctionalized key cyclitol compound containing branched-chains for the synthesis of TTX was prepared from d-glucose employing the Henry reaction (Nitro aldol reaction) as the key transformation. Stereoselective construction of the α-azido-aldehyde branched-chain was achieved via the key spiro