Synthesis and crystal structure of (±)-Goniotamirenone C.

The structure of the racemic version of the natural product Goniotamirenone C [racemic anti-6-(2-chloro-1-hy-droxy-2-phenyl-eth-yl)-2H-pyran-2-one, C13H11ClO3] at 150 K is reported. The compound crystallizes with monoclinic (P21/n) symmetry and with Z' = 2. One independent mol-ecule is ordered while the other independent mol-ecule exhibits an inter-esting whole-mol-ecule enanti-omeric disorder with occupancies of 0.846 (4) and 0.154 (4). The independent mol-ecules are hydrogen bonded with -OH⋯O=C linkages into chains that run parallel to the a axis. This structural analysis corrects our previous assignment as the syn isomer [Meesakul et al. (2020 ▸). Phytochemistry, 171, 112248-112255].