SYNTHESIS OF 2-(p-HYDROXYCINNAMOYL)-4-HYDROXY-4,6-DIMETHYLCYCLOHEXANE-1,3,5-TRIONE, AN ANALOG OF SAFFLOMIN A

Abstract

The synthesis of 2-(p-hydroxycinnamoyl)-4-hydroxy-4,6-dimethylcyclohexane-1,3,5-trione, an analog of safflomin A, was investigated.

Studies on the synthesis of safflomin-A, a yellow pigment in safflower petals: oxidation of 3-C-β-d-glucopyranosyl-5-methylphloroacetophenone

“…2). 8 Our interest was focused on the synthesis of the more natural model compound 5, in an attempt to verify the proposed structure of safflomin-A. The model compound 5 contains a C-b-D D-glucopyranosyl moiety linked to the a carbon between the 1,3-diketone carbons of quinochalcone.…”

Synthesis of (S)‐4‐C‐β‐D‐Glucosylquinochalcone: A Common Structure in the Yellow and Red Pigments of Safflower Petals

“…This oxidation method resulted in S ‐diastereoselectivity (de = 65%) and a moderate yield (52%), but not successful for the oxidation of C ‐glucosylphloroacetophenone for the synthesis of 1 (Route B, Scheme ). Oxidations using Pd (II) acetate , ammonium cerium (IV) nitrate , 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone , and Fremy's salt , as well as horseradish‐peroxidase catalyzed H 2 O 2 ‐oxidation, were also attempted: While oxidation of the disubstituted phloroaceophenone partially generated the desired oxidation product , oxidation of the monosubstituted phloroaceophenone was unsuccessful (Scheme ).…”

Chemical and Biological Properties of Quinochalcone C-Glycosides from the Florets of Carthamus tinctorius

“…In total synthesis of quinochalcone C -glycosides, asymmetric synthesis of carthamin (as the acetate) has been achieved [40], and the stereochemistry of its chiral carbon was determined to be S [41]. The total syntheses of the other yellow pigments of quinochalcone C -glycosides have not been carried out, but the synthesis of analogs in which the glucosyl group, or the glucosyl and hydroxyl groups on the chiral carbon were replaced by one or two methyl groups has been achieved for safflomin A [42], safflomin C [43], precarthamin [44], and carthamin [45].…”