Orcinol (I) was acetylated with Ac2O in pyridine to give diacetate (II), which was submitted to a Fries rearrangement in the presence of AlCl3 in chlorobenzene at 90 C to afford acetophenone (III). Subsequent condensation of (III) with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide (IV) was effected either in the presence of CdCO3 in boiling toluene or K2CO3 and tributyl benzylammonium chloride in CH2Cl2 at r.t. The resulting (glucopyranosyloxy)acetophenone (V) was condensed with 5-formylbenzofuran (VI) in the presence of KOH to give chalcone (VII). Hydrogenation of (VII) over Pt/C then yielded the (benzofuranyl)propiophenone (VIII). After protection of the 6'-hydroxyl group of (VIII) as the allyl ether (X) with allyl bromide (IX) and K2CO3, the primary alcohol of (X) was acylated with ClCOOMe to furnish carbonate ester (XI). Finally, the O-allyl group of (XI) was cleaved with palladium catalyst and ammonium formate.

Orcinol (I) is acetylated with Ac2O in pyridine giving the diacetate (II), which is submitted to a Fries rearrangement with AlCl3 in hot chlorobenzene yielding acetophenone (III). Subsequent condensation of (III) with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide (IV) by means of CdCO3 in refluxing toluene (or K2CO3 and tributylbenzylammonium chloride in dichloromethane) affords the glycosylated acetophenone (V), which is condensed with benzofuran-5-carbaldehyde (VI) by means of KOH in ethanol affording deacetylated chalcone (VII). Finally, this compound is hydrogenated with H2 over Pt/C in ethanol.

Orcinol (I) was acetylated with Ac2O in pyridine to give diacetate (II), which was submitted to a Fries rearrangement in the presence of AlCl3 in chlorobenzene at 90 C to afford acetophenone (III). Subsequent condensation of (III) with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide (IV) was effected either in the presence of CdCO3 in boiling toluene or K2CO3 and tributyl benzylammonium chloride in CH2Cl2 at r.t. The resulting (glucopyranosyloxy)acetophenone (V) was condensed with 5-formylbenzofuran (VI) in the presence of KOH to give chalcone (VII). Hydrogenation of (VII) over Pt/C then yielded the (benzofuranyl)propiophenone (VIII). After protection of the 6'-hydroxyl group of (VIII) as the allyl ether (X) with allyl bromide (IX) and K2CO3, the primary alcohol of (X) was acylated with ClCOOMe to furnish carbonate ester (XI). Finally, the O-allyl group of (XI) was cleaved with palladium catalyst and ammonium formate.

Orcinol (I) is acetylated with Ac2O in pyridine giving the diacetate (II), which is submitted to a Fries rearrangement with AlCl3 in hot chlorobenzene yielding acetophenone (III). Subsequent condensation of (III) with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide (IV) by means of CdCO3 in refluxing toluene (or K2CO3 and tributylbenzylammonium chloride in dichloromethane) affords the glycosylated acetophenone (V), which is condensed with benzofuran-5-carbaldehyde (VI) by means of KOH in ethanol affording deacetylated chalcone (VII). Finally, this compound is hydrogenated with H2 over Pt/C in ethanol.

Orcinol (I) was acetylated with Ac2O in pyridine to give diacetate (II), which was submitted to a Fries rearrangement in the presence of AlCl3 in chlorobenzene at 90 C to afford acetophenone (III). Subsequent condensation of (III) with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide (IV) was effected either in the presence of CdCO3 in boiling toluene or K2CO3 and tributyl benzylammonium chloride in CH2Cl2 at r.t. The resulting (glucopyranosyloxy)acetophenone (V) was condensed with 5-formylbenzofuran (VI) in the presence of KOH to give chalcone (VII). Hydrogenation of (VII) over Pt/C then yielded the (benzofuranyl)propiophenone (VIII). After protection of the 6'-hydroxyl group of (VIII) as the allyl ether (X) with allyl bromide (IX) and K2CO3, the primary alcohol of (X) was acylated with ClCOOMe to furnish carbonate ester (XI). Finally, the O-allyl group of (XI) was cleaved with palladium catalyst and ammonium formate.