Crystal structure and Hirshfeld analysis of (1a S,3a R,4a S,5a R)-15-acet-oxy-linden-7(11),8-trieno-12,8-lactone

Qiang-Qiang Lu; Xin-Wei Shi; Ya-Fu Zhou; Xin-Ai Cui; Hong Wang

doi:10.1107/S2056989022004625

Crystal structure and Hirshfeld analysis of (1a S,3a R,4a S,5a R)-15-acet-oxy-linden-7(11),8-trieno-12,8-lactone

Acta Crystallogr E Crystallogr Commun. 2022 May 20;78(Pt 6):642-646. doi: 10.1107/S2056989022004625. eCollection 2022 Jun 1.

Authors

Qiang-Qiang Lu¹, Xin-Wei Shi¹, Ya-Fu Zhou¹, Xin-Ai Cui¹, Hong Wang¹

Affiliation

¹ Shaanxi Engineering Research Centre for Conservation and Utilization of Botanical Resources, Xi'an Botanical Garden of Shaanxi Province (Institute of Botany of Shaanxi Province), Xi'an 710061, People's Republic of China.

Abstract

The structure of the title com-pound, C₁₇H₂₀O₄ [systematic name: (1aS,3aR,4aS,5aR)-15-(acet-oxy)linden-7(11),8-trieno-12,8-lactone or (4aR,5S,5aR,6aS,6bR)-5-(acet-oxy-meth-yl)-4a,5,5a,6,6a,6b-hexa-hydro-3,6b-di-methyl-cyclo-propa[2,3]indeno-[5,6-b]furan-2(4H)-one, ent-chloranthalactone C], a natural product iso-lated from the whole plant Chloranthus japonicus Sieb., is a typical lin-den-ane-type sesquiterpenoid. The mol-ecule com-prises a bi-cyclo-[3.1.0]hexane ring (A/B system) bearing an acetoxymethyl (C-4) group, a bi-cyclo-[4.3.0]nonane ring (B/C system) containing a double bond (C-8/9) and a chiral quaternary carbon (C-10), and a 7(11)-en-12,8-olide structural moiety on the cyclo-hexan-8-ene (C ring). In the tetra-cyclic skeleton, the 1,3-cyclo-propane ring has a β-con-figuration, and atoms H-5 and H₃-14 have α- and β-orientations, respectively. In the crystal, the mol-ecules are assembled into a two-dimensional network by weak O⋯H/H⋯O inter-actions. Hirshfeld surface analysis illustrates that the greatest contributions are from H⋯H (55.2%), O⋯H/H⋯O (34.6%) and C⋯H/H⋯C (8.9%) contacts.

Keywords: Chloranthus japonicus; crystal structure; polycyclic framework; sesquiterpenes.

Grants and funding

Funding for this research was provided by: Natural Science Basic Research Program of Shaanxi (grant Nos. 2020JM-708 and 2021JQ-968); Science and Technology Program of Shaanxi Academy of Sciences (grant Nos. 2018nk-01 and 2018k-11); Xi’an Science and Technology Plan Project (grant No. 20NYYF0043).