Pentafluorophenyl (3R,4R,5R)-5-{[(3R,4R,5R)-5-azidomethyl-3,4-dimethoxy-2,3,4,5-tetrahydro -furan-3-carbonylamino]methyl}-3,4-dimethoxy-2,3,4,5-tetrahydrofuran-3-c arboxylate

The crystal structure of the title compound, C(22)H(25)F(5)N(4)O(9), an important intermediate in the synthesis of novel biopolymers containing branched carbon chains, establishes the relative stereochemistry at all six chiral centres of the dipeptide. The structure may indicate a predisposition to the organization of secondary structure by novel dipeptide isosteres. An intermolecular hydrogen bond between the NH group and one of the N atoms of the azide group contributes to the stabilization of the packing. RI Simone, Michela/A-6887-2011; Punzo, Francesco/A-4921-2011 OI Punzo, Francesco/0000-0003-4212-8064