Regioselective cleavage of the bis-benzylidene acetal of d-mannitol under oxidative and reductive conditions: a new approach to C2-symmetric chiral ligands

Abstract A highly regioselective oxidative cleavage of 1,3:4,6-di- O -benzylidene- d -mannitol was carried out using NBS and the resultant product was readily converted to the C 2 -symmetric chiral ligand, ( R , R )-3,4-dihydroxy-1,5-hexadiene. On the other hand, reductive cleavage of 1,3:4,6-di- O -benzylidene- d -mannitol was achieved in a highly regioselective manner using BF 3 ·OEt 2 and Et 3 SiH to give a highly functionalized benzyl ether, which was converted to a synthetically useful C 2 -symmetric bis-amino alcohol derivative.