rac-6-Hy-droxy-2,5,7,8-tetra-methyl-chroman-2-carboxamide from synchrotron data.

The crystal structure of the title water-soluble analogue of vitamin E, trolox amide, C(14)H(19)NO(3), solved and refined against synchrotron diffraction data, contains two mol-ecules in the asymmetric unit. In both molecules, the heterocyclic ring is in a half-chair conformation. The crystal packing features a herring-bone pattern generated by N-H⋯O hydrogen bonds between the hy-droxy and amide groups. O-H⋯O hydrogen bonds also occur.