STUDIES ON THE SYNTHESIS ARMILLARISIN A

A practical method for the preparation of Armillarisin A is described. The key intermediate, 3, 5-dihydroxyphenylcarbinol, was prepared through etherification of methyl 3, 5-dihydroxybenzoate with benzylchloride in the presence of potassium carbonate and catalytic amount of potassium iodide, and then reduction of the etherified product by potassium boronhydride-Lithium chloride, and finally debenzylation by hydrogenation over 5% Pd/C, the yield of this step being 71%.Armillarisin A was prepared through the direct condensation of 3, 5-dihydroxyphenylcarbinol with ethyl ethoxymethylene acetylacetate in the presence of sodium ethoxide, the yield being 60～70%. The overall yield was 40% (on the basis of benzoic acid).