organic compounds
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The asymmetric unit of the title compound, C20H18N2O2, contains two independent molecules in which the dihedral angles between the naphthalene ring system [r.m.s. deviations = 0.012 (1) and 0.015 (1) Å] and the benzene ring are 71.65 (6) and 74.51 (6)°. In the crystal, pairs of N—HO hydrogen bonds form two independent inversion dimers with graph-set notation R22(14). In addition, each molecule contains an intramolecular O—HN hydrogen bond with an S(6) motif.
data reports
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In the structure of the title compound, C12H12O3, the dihydropyran ring is fused with the benzene ring. The dihydropyran ring is in a half-chair conformation, with the ring O and methylene C atoms positioned 1.367 (3) and 1.504 (4) Å, respectively, on either side of the mean plane formed by the other four atoms. The methoxy group is coplanar with the benzene ring to which it is connected [Cb—Cb—Om—Cm torsion angle = −0.2 (4)°; b = benzene and m = methoxy], and similarly the aldehyde is coplanar with respect to the double bond of the dihydropyran ring [Cdh—Cdh—Ca—Oa = −178.1 (3)°; dh = dihydropyran and a = aldehyde]. In the crystal, molecules are linked by weak methyl–methoxy C—HO hydrogen bonds into supramolecular chains along the a-axis direction.
data reports
Open access
In the title compound, C17H14O5, the dimethoxy-substituted benzene ring is twisted relative to the 4H-chromenon skeleton (r.m.s. deviation = 0.015 Å) by 5.2 (4)°. The C atoms of the methoxy groups lie close to the plane of their attached benzene ring [deviations = 0.036 (3) and 0.290 (3)Å for the meta and para substituents, respectively]. An intramolecular O—HO hydrogen bond closes an S(5) ring. In the cystal, inversion dimers linked by pairs of O—HO hydrogen bonds generate R22(10) loops and C—HO interactions connect the dimers into [010] chains.