ChemInform Abstract: CHOLERETISCHE CHALKONE, SYNTH., SPEKTROSKOPISCHE UNTERSUCHUNG, PHARMAKOLOGISCHE EIGENSCHAFTEN

Abstract

Die Kondensation der Aldehyde (I) mit dem Acetophenon (II) liefert in alkalischem Medium die Chalkone (III) (35‐78% Ausbeute).

Mechanism of cyclization of substituted 2′-hydroxychalcones to flavanones

“…5% NaOH (30 ml) was then added (pH 14) and the mixture was stirred for 2 min until the mixture turned red. The mixture was acidified and worked up in the way described for compound (3). The residue was chromatographed on a Kieselgel 40 silica gel (70-230 mesh) column with benzen-hloroform (2 : 1) as eluant.…”

“…A rapid equilibrium (K,) is established between the substrate and its anion and the overall rate of the substrate disappearance has the form (7) for compound (3). The limiting conditions of (7) equation ( 7) are equations ( 5) and (6) at low and high pH respectively, which account for the experimental results.…”