De Novo Synthetic Approach to 2,4-Diamino-2,4,6-trideoxyhexoses (DADTH): Bacterial and Rare Deoxy-Amino Sugars.

A synthetic route to 2,4-diamino-2,4,6-trideoxysugar stereoisomers in 6-7 steps and 22-33% overall yield is described. A key step in this pathway is the carbonyl coupling of d- and l-threoninol or d- and l- allo -threoninol to a phthalimido-allene mediated by chiral iridium-H 8 -BINAP, which allows for installation of two new chiral centers in one, highly diastereoselective (>20:1 dr) step. This approach provides a more concise, diastereoselective, and versatile method to access these deoxy-amino sugars than is currently available.