tert-Butyl N-{(1S)-1-[(2,4-dihy-droxy-benzyl-idene)hydrazinecarbon-yl]-2-hy-droxy-eth-yl}carbamate ethanol monosolvate.

The mol-ecule of the title ethanol solvate, C(15)H(21)N(3)O(6)·C(2)H(6)O, adopts a curved shape; the conformation about the imine bond [N=N = 1.287 (3) Å] is E. The amide residues occupy positions almost orthogonal to each other [dihedral angle = 85.7 (2)°]. In the crystal, a network of O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds leads to the formation of supra-molecular arrays in the ab plane with the ethanol mol-ecules lying to the periphery on either side. Disorder in the solvent ethanol mol-ecule was evident with two positions being resolved for the C atoms [site occupancy of the major component = 0.612 (10)].