(4S,5R,6R)-Methyl 4-hydr-oxy-4,5-iso-propyl-idenedioxy-4,5,6,7-tetra-hydro-1,2,3-triazolo[1,5-a]pyridine-3-carboxyl-ate.

X-ray crystallography confirmed the structure of the title triazole, C(11)H(15)N(3)O(5), formed from a single-step reaction of a sugar azide with a brominated ylid. The absolute configuration was determined by the use of d-ribose as the starting material. The six-membered ring is in a half-chair conformation. The crystal structure exists as chains of O-H⋯O hydrogen-bonded moleclues running parallel to the b axis.