(R)-(−)-Quinuclidin-3-ol

The structure of the title compound [alternatively called (R)-(−)-1-aza­bicyclo­[2.2.2]octan-3-ol], C₇H₁₃NO, at 100 K has hexa­gonal (P6₁) symmetry. The structure shows a twist along the C—N pseudo-threefold axis. In the crystal, mol­ecules are linked via O—H...N hydrogen bonds, forming infinite chains along the c-axis direction. The crystal studied was twinned by merohedry (twin law: 010, 100, 00-1; population: 0.925:0.075)

A triclinic polymorph of (−)-(S)-N-benzyl-2-[(R)-6-fluoro­chroman-2-yl]-2-hy­droxy­ethanaminium bromide

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 mol­ecules 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 hy­droxy-bearing C atom and R for the asymmetric C atom in the di­hydro­pyran 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.