The condensation of phloroglucinol (I) with 4-methoxycarbonyloxy)cinnamoyl chloride (II) by means AlCl3 in hot nitrobenzene gives 4'-O-methoxycarbonylnaringenin (III), which is hydrolyzed with NH3 in water-acetone.
The condensation of 2,4,6-trihydroxyacetophenone (IV) with tetraacetylbromoglucose (V) by means of NaOH in acetone-water gives tetraacetylphloracetophenone-4-O-glucoside (VI), which is condensed with 4-hydroxybenzaldehyde (VII), by means of KOH in alcohol yielding the chalcone derivative (VIII). Finally, this compound is cyclized and deprotected by a treatment with refluxing aqueous HCl.