Chalcone epoxide intermediates in the syntheses of lignin-related phenylcoumarans
Journal article, 2006

Compounds (2R*,3S*)-1-(3,4-dimethoxyphenyl)-3-{3-methoxy-2-[(2R*)-tetrahydropyran-2-yloxy]phenyl}-2,3-epoxy-1-propanone, C23H26O7, (I), and trans-1-(3,4-dimethoxyphenyl)-3-[3-methoxy-2-(methoxymethoxy)phenyl]-2,3-epoxy-1-propanone, C20H22O7, (II), were obtained on epoxidation of chalcones. The stereochemistries of (I) and (II) were elucidated. In both compounds, the substituents on the oxirane ring are trans-oriented. Compound (I) was obtained together with a diastereometric form that differs from (I) with respect to the configuration of the asymmetric C atom in the tetrahydropyran group. The geometries of the substituted oxirane rings of (I) and (II) are very similar. The hydrogen-bonding patterns, mediated via weak C-H...O interactions, differ considerably. The crystal structures of (I) and (II) are compared with those of related chalcone epoxides. The conversion of (I) and (II) into lignin-related phenylcoumarans is discussed.

hydrogen bonds

conformation

stereochemistry

X-ray strucrure determination

Author

Vratislav Langer

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Shiming Li

Chalmers, Chemical and Biological Engineering, Forest Products and Chemical Engineering

Knut Lundquist

Chalmers, Chemical and Biological Engineering, Forest Products and Chemical Engineering

Acta Crystallographica Section C: Crystal Structure Communications

0108-2701 (ISSN) 1600-5759 (eISSN)

Vol. C62 10 o625-o627

Subject Categories

Organic Chemistry

DOI

10.1107/S0108270106036900

More information

Created

10/7/2017