Regioselective and diastereoselective amination of polybenzyl ethers using chlorosulfonyl isocyanate: Total syntheses of 1,4-dideoxy-1,4-imino-d-arabinitol and (-)-lentiginosine

The total syntheses of DAB1 (1) and (-)-lentiginosine (2) were concisely accomplished from D-lyxose via regioselective and diastereoselective NHCbz introduction using CSI, chemoselective removal of the Cbz protection, and ring-closing metathesis as key steps.