Total synthesis of the pyranocoumaronochromone lupinalbin H

The pyranocoumaronochromone lupinalbin H was synthesized in three major steps, which involved preparation of 2′-hydroxygenistein by the Suzuki-Miyaura reaction, followed by oxidative cyclodehydrogenation into lupinalbin A. The final step was the regiospecific introduction of the dimethylpyran moiety to ring A of lupinalbin A via an aldol-type condensation with 3-methyl-2-butenal and 6π-electrocyclization.

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