Z-Pulvinones

Earlier, Knight and Pattenden 419, 421) had synthesised the per-methyl derivative (121) of the pigment (115) from the metallated te-tronic acid (120) and 3,4-dimethoxybenzaldehyde as shown in Scheme 18. Subsequently, the anti-inflammatory properties of several pulvinone derivatives have been recognised and a further synthesis of ( )- and (Z)-pulvinones has been developed 153),... 

A highly diastereoselective method for the synthesis of tetronic acids has heen developed based upon a tandem Claisen condensation/transesterification between arylacetate enolates and arylmethylene-substituted 2,2-dimethyl-l,3-dioxolan-4-ones. The versatility of this method has been demonstrated in an improved synthesis of (Z)-configured pulvinones (Equation 58) <20078118>. 

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