Crystal structure of (-)-(5R,7R,8S,9R,10S)-8-methyl-7-[(5R)-3-methyl-2-oxooxolan-3-en-5-yl]-1-aza-6-oxatri-cyclo-[8.3.0.05,9]tridecan-13-one monohydrate.

Takeshi Oishi,Noritaka Chida,Makoto Yoritate,Takaaki Sato

doi:10.1107/s2056989018004425

Takeshi Oishi, Noritaka Chida + Show 2 more

Open Access

https://doi.org/10.1107/s2056989018004425

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Abstract

The title compound, C17H23NO4·H2O, is an epimer of the natural tetra-cyclic alkaloid isosaxorumamide which consists of a fused 5-7-5 tricyclic core and a di-hydro-furan-one substituent. The terminal di-hydro-furan ring is essentially planar with a maximum deviation of 0.0273 (14) Å from the mean plane and oxolane, azepane and pyrrolidine rings in the tricyclic ring system adopt twist, twist-chair and envelope forms, respectively. In the crystal, the amide and water mol-ecules are linked by O-H⋯O hydrogen bonds, forming a tape structure running along the b-axis direction. The tapes are further connected by C-H⋯O inter-actions into a three-dimensional architecture.

Highlights

The title compound, C17H23NO4ÁH2O, is an epimer of the natural tetracyclic alkaloid isosaxorumamide which consists of a fused 5–7–5 tricyclic core and a dihydrofuranone substituent
The terminal dihydrofuran ring is essentially planar with a maximum deviation of 0.0273 (14) Afrom the mean plane and oxolane, azepane and pyrrolidine rings in the tricyclic ring system adopt twist, twist-chair and envelope forms, respectively
The amide and water molecules are linked by O—HÁ Á ÁO hydrogen bonds, forming a tape structure running along the b-axis direction

Summary

Chemical context

Saxorumamide and isosaxorumamide are natural Stemona alkaloids isolated from the root of Stemona Saxorum (Wang et al, 2007). They are a pair of diastereomer (12-epimer of each other) which consist of a fused octahydrofuro[3,2-c]pyrrolo[1,2-a]azepane nucleus with a dihydrofuranone substituent (Fig. 1). The Stemona alkaloids have been isolated from various Stemonaceae species, and over 150 metabolites have. Extracts of Stemonaceae plants have been traditionally used for folk medicines as antitussive and anthelmintic agents in the wide regions of East Asia and Southeast Asia (Greger, 2006). Stemona Saxorum has been utilized for endemic disease in Vietnam. Symmetry codes: (i) x À 1; y; z; (ii) Àx þ 2; y À 12; Àz þ 12; (iii) x; y þ 1; z; (iv) x þ 12; Ày þ 12; Àz

Structural commentary

Supramolecular features

Database survey

Synthesis and crystallization