Chalcone epoxide intermediates in the syntheses of lignin-related phenylcoumarans
Artikel i vetenskaplig tidskrift, 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

Författare

Vratislav Langer

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Shiming Li

Chalmers, Kemi- och bioteknik, Skogsindustriell kemiteknik

Knut Lundquist

Chalmers, Kemi- och bioteknik, Skogsindustriell kemiteknik

Acta Crystallographica Section C: Crystal Structure Communications

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

Vol. C62 10 o625-o627

Ämneskategorier

Organisk kemi

DOI

10.1107/S0108270106036900