Expanding the\nScope of a One-Pot Double Displacement\nProtocol to Access the All-Rare-Sugar-Containing Trisaccharide Unit\nof <i>Pseudomonas stutzeri</i> OX1

Herein, we have explored a one-pot bis-triflation and\nregioselective\ndisplacement protocol with d-fucose 2,4-diol to access various\nrare 6-deoxy amino d-sugars. This strategy enabled the first\ntotal synthesis of the trisaccharide unit of <i>Pseudomonas stutzeri</i> OX1 strain containing d-perosamine and d-tomosamine.\nInstallation of a 1,2-<i>cis</i> linkage and late-stage <i>N</i>-formylation are the key challenges in the total synthesis,\nwhich was accomplished via the longest linear sequence of 21 steps\nwith 1.2% overall yield.