title: (3S,4S)-3-Ethyl-4-hydr-oxy-3-(3-methoxy-phen-yl)-1-methyl-azepan-1-ium d-tartrate dihydrate.
abstract: In the title compound, C(16)H(26)NO(2) (+)·C(4)H(5)O(6) (-)·2H(2)O, a meptaz-inol derivative, three C atoms of the azepane ring are disordered over two positions, with site-occupancy factors of 0.80 and 0.20; the major disorder component adopts a twist-chair conformation, while the minor component has a chair conformation. The benzene ring is axially substituted on the heterocyclic ring, resulting in a folded conformation of the cation. The absolute configuration was determined with reference to d-tartaric acid. The crystal structure is stabilized by an extensive network of intra- and inter-molecular O-H⋯O hydrogen bonds.
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 138 Yixueyuan Road, Shanghai 200032, People's Republic of China.
authors.forename: Xing-Hai
authors.initials: XH
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Chao
authors.forename: Zhui-Bai
authors.initials: ZB
authors.lastname: Qiu