Potassium Hydroxide → 2'-(beta-D-glucopyranosyloxy)-6'-hydroxy-3-(5-benzo[b]furanyl)acrylophenone

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Reaction Steps

2'-(2,3,4,6-Tetra-O-acetyl-α-D-glucopyranosyloxy)-6'-hydroxyacetophenone (5 g) and benzo[b]furan-5-carbaldehyde (1.81 g) are (i) treated in the same manner as in Example 1 to give crude 2'-(β-D-glucopyranosyloxy)-6'-hydroxy-3-(5-benzo[b]furanyl)acrylophenone, which is dissolved in a mixture of ethanol (50 ml) and a 10% aqueous potassium hydroxide solution (10 ml). The mixture is subjected to catalytic hydrogenation by using as a catalyst platinum oxide (120 mg) under atmospheric pressure. The catalyst is removed by filtration, and the filtrate is neutralized with a 10% hydrochloric acid under ice-cooling, and concentrated under reduced pressure. To the residue is added ethyl acetate, and the mixture is stirred, and the organic layer is collected; (ii) treated in the same manner as in Example 1 to give crude 2'-(β-D-glucopyranosyloxy)-6'-hydroxy-3-(5-benzo[b]furanyl)acrylophenone, which is dissolved in a mixture of ethanol (50 ml) and a 10% aqueous potassium hydroxide solution (10 ml). To the solution is added 4-N,N-diemethylaminopyridine (2.5 g) and the mixture is subjected to catalytic hydrogenation by using as a catalyst 10% palladium-carbon (1.1 g) under atmospheric pressure. The catalyst is removed by filtration, and the filtrate is neutralized with a 10% hydrochloric acid under ice-cooling, and concentrated under reduced pressure. To the residue is added ethyl acetate, and the mixture is stirred, and the organic layer is collected; or (iii) treated in the same manner as in Example 2, and the organic layer is collected.

Provenance & Evidence