ABSTRACT
A series of novel pyranochromene chalcones and corresponding flavanones were synthesized. This is the first report on the confirmation of the absolute configuration of chromene-based flavanones using X-ray crystallography. These compounds were characterized by 2D NMR spectroscopy, and their assignments are reported herein. The 3D structure of the chalcone 3b and flavanone 4g was determined by X-ray crystallography, and the structure of the flavanone was confirmed to be in the S configuration at C-2.
Subject(s)
Algorithms , Benzopyrans/chemical synthesis , Chalcones/chemical synthesis , Crystallography, X-Ray/methods , Flavanones/chemical synthesis , Magnetic Resonance Spectroscopy/methods , Benzopyrans/analysis , Binding Sites , Chalcones/analysis , Flavanones/analysis , Molecular ConformationABSTRACT
In the biologically active title compound, C26H26O5, the pyran ring of the chromene unit adopts a half-chair conformation. The C=C double bond of the propenone unit exhibits a trans conformation and the carbonyl group is syn conformation to the double bond. The dihedral angle between the benzene ring and the benzopyran-one moiety is 31.54â (4)°. The mol-ecular structure is stabilized by an intra-molecular C=Oâ¯H-O hydrogen bond.
ABSTRACT
In the title compound, C(18)H(20)O(4),the pyran ring of the chromene unit adopts a half-chair conformation. An intra-molecular O-Hâ¯O hydrogen bond occurs. In the crystal, mol-ecules are linked along the b axis by C-Hâ¯O hydrogen bonds.
ABSTRACT
In the title compound, C(17)H(13)FO(3), the dihedral angle between the benzene rings is 70.34â (5)°. In the crystal, molecules are linked via pairs of bifurcated C-Hâ¯(O,O) hydrogen bonds, forming inversion dimers. These dimers are linked via C-Hâ¯O and C-Hâ¯F inter-actions, forming a three-dimensional structure.
ABSTRACT
In the title compound, C(16)H(20)N(2)S, a potential tetra-hydro-isoquinoline (TIQ) thia-zole ligand, the N-containing six-membered ring of the TIQ unit adopts a half-chair conformation. There are four mol-ecules in the asymmetric unit. No classical hydrogen bonds or π-π inter-actions were found in the crystal structure.
ABSTRACT
The title compound, C(9)H(10)Br(2)O(2), crystallizes with two mol-ecules in the asymmetric unit. The two mol-ecules are essentially planar with slight differences in the (Br)C-C-O-C(H(3)) torsion angles [-176.7â (2) and -172.8â (2)° in one mol-ecule and 174.8â (2) and 179.9â (2)° in the other]. The crystal structure consists of sheets of mol-ecules linked through Brâ¯Br [3.3547â (4), 3.3703â (4) and 3.5379â (4)â Å] inter-actions, which are in turn connected through π-π inter-actions with centroid-centroid distances of 3.5902â (14) and 3.5956â (14)â Å.
ABSTRACT
In the title compound, C(18)H(16)N(2)S, the N-containing ring adopts a half-chair configuration. The crystal packing features C-Hâ¯N contacts. There is no π-π stacking within the crystal structure.
ABSTRACT
In the title compound, C(26)H(24)N(2)O(2)S, the dihedral angle between the thia-zole ring and the adjacent phenyl ring is 3.02â (15)°. The N-containing six-membered ring of the tetra-hydro-isoquinoline unit adopts a half-chair conformation. The dihedral angle between the least-squares plane of the tetra-hydro-isoquinoline ring system and its nearest phenyl ring is 76.90â (13)°. No classical hydrogen bonds nor π-π inter-actions were found in the crystal structure.