ABSTRACT: The title compound, C19H20O6, consists of a tetra-substituted benzene ring with one substituent being an ?,?-unsaturated cinnamoyl group, which forms an extended conjugated system in the mol-ecule. In addition, two meth-oxy-meth-oxy and one hy-droxy group are bonded to the central benzene ring. The dihedral angle between eh rings is 10.22?(10)°. An intra-molecular hydrogen bond is observed between the hy-droxy group and the carbonyl O atom. One of the meth-oxy-meth-oxy substituents is conformationally disordered over two sets of sites with site-occupation factors of 0.831?(3) and 0.169?(3).
Project description:The reaction of 5,6-(2,2-dimethyl-chroman-yl)-2-hy-droxy-4-meth-oxy-acetophenone and 3,4-bis-(meth-oxy-meth-yloxy)benzaldehyde affords the intense orange title chalcone derivative, C(25)H(30)O(8). The two benzene rings are connected through a -C(=O)-CH=CH- (propenone) unit, which is in an E conformation; the ring with the hy-droxy substitutent is aligned at 19.5?(2)° with respect to this unit, whereas the ring with the meth-oxy-meth-yloxy substituent is aligned at 9.3?(3)°. The dihedral angle between the rings is 19.38?(10)°. The hy-droxy group engages in an intra-molecular O-H?O hydrogen bond with the carbonyl O atom of the propenone unit, generating an S(5) ring.
Project description:The title compound, C(19)H(18)O(7) [systematic name 5-hy-droxy-3,6,7-tri-meth--oxy-2-(4-meth-oxy-phen-yl)-4H-1-benzopyran-4-one], is a flavonoid which was isolated from the traditional Chinese medicine Laggera alata. The benzene ring of the benzopyran-one unit forms dihedral angles of 1.72?(3) and 37.39?(5)° with the pyran ring and the substituent benzene ring, respectively. The mol-ecular conformation is stabilized by an intra-molecular phenol O-H?O(ketone) hydrogen bond.
Project description:In the mol-ecule of the title benzohydrazide derivative, C(17)H(18)N(2)O(4), the dihedral angle between the benzene rings is 6.86?(11)°. The meth-oxy group of the 4-meth-oxy-phenyl fragment deviates slightly [C(methyl)-O-C-C = 10.0?(4)°] with respect to the benzene ring, whereas the eth-oxy group of the 3-eth-oxy-4-hy-droxy-phenyl fragment is is almost coplanar [C-O-C-C(methyl) = 178.5?(2)°]. In the crystal, mol-ecules are linked by N-H?O, O-H?O and C-H?O hydrogen bonds into a two-dimensional network parallel to the ab plane. C-H?? inter-actions and C?O [2.980?(3)?Å] short contacts are also observed.
Project description:In the title compound, C8H10O3, the hy-droxy-methyl group is twisted by 74.51?(13)° from the plane of the benzene ring to which it is connected. By contrast, the benzene and meth-oxy groups are almost coplanar, making a dihedral angle of 4.0?(2)°. In the crystal, O-H?O hydrogen bonds link the mol-ecules into a three-dimensional network.
Project description:In the title compound, C(15)H(13)BrN(2)O(3)·H(2)O, the dihedral angle between the two benzene rings is 13.92?(6)°. The meth-oxy group of the 4-hy-droxy-3-meth-oxy-phenyl is almost coplanar with its bound benzene ring, as seen by the C(meth-yl)-O-C-C torsion angle of -0.35?(16)°. In the crystal, mol-ecules are linked into a three-dimensional network by N-H?O, O-H?N and O-H?O hydrogen bonds and also weak C-H?O inter-actions. A short C?O contact of 3.0191?(15)?Å is also present.
Project description:The title compound, C(16)H(14)O(5)·2H(2)O [systematic name: 5-hy-droxy-2-(4-hy-droxy-phen-yl)-7-meth-oxy-chroman-4-one dihydrate], is a natural phytoalexin flavone isolated from the native chilean species Heliotropium taltalense and crystallizes with an organic mol-ecule and two water mol-ecules in the asymmetric unit. The 5-hy-droxy group forms a strong intra-molecular hydrogen bond with the carbonyl group, resulting in a six-membered ring. In the crystal, the components are linked by O-H?O hydrogen bonds, forming a three-dimensional network. The 4-hy-droxy-phenyl benzene ring is bonded equatorially to the pyrone ring, which adopts a slightly distorted sofa conformation. The title compound is the hydrated form of a previously reported structure [Shoja (1990 ?). Acta Cryst. C46, 1969-1971]. There are only slight variations in the mol-ecular geometry between the two compounds.
Project description:The planar -CH=CHC(=O)- fragment (r.m.s. deviation = 0.074?Å) in the title compound, C(18)H(18)O(5), connects the planar hy-droxy-dimeth-oxy-phenyl (r.m.s. deviation = 0.039?Å) and meth-oxy-lphenyl (r.m.s. deviation = 0.021?Å) parts. The central fragment forms a dihedral angle of 13.7?(1)° with the hy-droxy-dimeth-oxy-phenyl part and 32.0?(1)° with the meth-oxy-phenyl part. The hy-droxy group forms an intra-molecular hydrogen bond to the carbonyl O atom.
Project description:The reaction of 5,6-(2,2-dimethyl-chromane)-2-hy-droxy-4-meth-oxy-acetophenone and 3,4-methlene-dioxy-benzaldehyde affords the title chalcone derivative, C(22)H(22)O(6). The two benzene rings are connected through a -C(=O)-CH=CH- (propenone) unit, which is in an E conformation; the ring with the hy-droxy substitutent is aligned at 6.2?(1)° with respect to this unit, whereas the ring with the methyl-enedi-oxy substituent is aligned at 8.2?(1)°. The dihdral angle between the rings is 14.32?(7)°. The hy-droxy group engages in an intra-molecular hydrogen bond with the carbonyl O atom of the propenone unit, generating an S(5) ring.
Project description:The crystal structures of four (E)-meth-oxy-benzaldehyde oxime derivatives, namely (2-meth-oxy-benzaldehyde oxime, 1, 2,3-di-meth-oxy-benzaldehyde oxime, 2, 4-di-meth-oxy-benzaldehyde oxime, 3, and 2,5-di-meth-oxy-benzaldehyde oxime, 4, are discussed. The arrangements of the 2-meth-oxy group and the H atom of the oxime unit are s-cis in compounds 1-3, but in both independent mol-ecules of compound 4, the arrangements are s-trans. There is also a difference in the conformation of the two mol-ecules in 4, involving the orientations of the 2- and 5-meth-oxy groups. The primary inter-molecular O-H(oxime)?O(hy-droxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O-H(oxime)?O(hy-droxy) hydrogen bonds generate symmetric R 2 2(6) dimers. A more complex dimer is generated in 4 from the O-H(oxime)?O(hy-droxy) and C-H(2-meth-oxy)?O(hy-droxy) hydrogen bonds. In all cases, further inter-actions, C-H?O and C-H?? or ?-?, generate three-dimensional arrays. Hirshfeld surface and fingerprint analyses are discussed.
Project description:Herein, the synthesis and crystal structure of 7-hy-droxy-3-(2-meth-oxy-phen-yl)-2-tri-fluoro-meth-yl-4H-chromen-4-one, C17H11F3O4, are reported. This isoflavone is used as a starting material in the preparation an array of potent and competitive FPR antagonists. The pyran ring significantly deviates from planarity and the dihedral angle between the benzo-pyran mean plane and that of the exocyclic benzene ring is 88.18?(4)°. In the crystal, O-H?O hydrogen bonds connect the mol-ecules into C(8) chains propagating in the  direction.