title: (25R)-6α-Hy-droxy-5α-spiro-stan-3β-yl tosyl-ate.
abstract: The title steroid, C34H50O6S, is an inter-mediate on the synthetic route between diosgenin and brassinosteroids, which possess the A ring modified with the 2α,3α-diol functionality. The polycyclic spiro-stan system has the expected conformation, with six-membered rings adopting chair forms and the five-membered rings envelope forms (flap atoms are the methine C atom in the C/D-ring junction and the spiro C atom connecting rings E and F). The 3β-tosyl-ate group is oriented in such a way that S=O bonds are engaged in inter-molecular hydrogen bonds with O-H and C-H donors. Chains of mol-ecules are formed along [100] via O-H⋯O hydrogen bonds, and secondary weak C-H⋯O inter-actions connect two neighbouring chains in the [001] direction.
authors.affiliation: Benemérita Universidad Autónoma de Puebla, Facultad de Ciencias Químicas, Ciudad Universitaria, Puebla, Pue. 72570, Mexico.
authors.forename: María A
authors.initials: MA
authors.lastname: Fernández-Herrera
authors.forename: Jesús
authors.initials: J
authors.lastname: Sandoval-Ramírez
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bernès
authors.forename: Maricela
authors.initials: M
authors.lastname: Rodríguez-Acosta
authors.forename: María-Guadalupe
authors.initials: MG
authors.lastname: Hernández Linares