Abstract
The title salt, C18H21FNO2 (+)·Br(-), determined at 115 K, crystallizes in the triclinic space group P1. The previously reported polymorph occurs in the monoclinic space group P21 and has two independent mol-ecules in the asymmetric unit [Peeters et al. (1993 ▶). Acta Cryst. C49, 2157-2160]. In the title molecule, the pyran rings adopt half-chair conformations. The absolute configuration is S for the hy-droxy-bearing C atom and R for the asymmetric C atom in the di-hydro-pyran unit. In the crystal, the components are linked by N-H⋯Br and O-H⋯Br hydrogen bonds, forming chains along the c-axis direction. The crystal studied was refined as an inversion twin.