Crystal structure of a photobiologically active brominated angular pyran-ocoumarin: bromo-hy-droxy-seselin.
The title compound, C14H13BrO3[systematic name:rac-(9S,10R)-9-bromo-10-hy-droxy-8,8-dimethyl-9,10-di-hydro-2H,8H-pyrano[2,3-f]chromen-2-one], is a substituted pyran-ocoumarin, obtained by bromination of seselin [8,8-dimethyl-2H,8H-pyrano[2,3-f]chromen-2-one], which was isolated from the Indian herbTrachyspermum stictocarpum(Aajmod). The pyrano ring has a distorted half-chair conformation and its mean plane is inclined to the coumarin mean plane by 1.6 (2)°. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, forming inversion dimers with anR22(16) ring motif. The dimers stack along thea-axis direction and are linked by offset π-π inter-actions, forming columns [inter-centroid distance = 3.514 (4) Å].
Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
A K
https://orcid.org/0000-0002-0941-5638
AK
Bauri
Institute of Materials Science, Darmstadt University of Technology, Alarich-Weiss-Strasse 2, D-64287 Darmstadt, Germany.
Sabine
https://orcid.org/0000-0001-8341-0205
S
Foro
Department of Applied Chemistry & Chemical Engineering, University of Dhaka, Dhaka, Dhaka-1000, Bangladesh.
A F M Mustafizur
https://orcid.org/0000-0002-1712-3141
AF
Rahman
bromination; crystal structure; hydrogen bonding; offset π–π inter­actions; seselin