Hydrochloric Acid → methyl 2-(4-ethoxy-3-[(2S,3S,4R,5R,6R)-3,4,5-tris(acetyloxy)-6-[(acetyloxy)methyl]tetrahydro-2H-pyran-2-yl]benzyl)azulene-1-carboxylate

Participants

Reaction Steps

Two drops of 1,2-dibromoethane was added to a suspension of zinc powder (0.17 g) in THF (5.0 ml) in an argon atmosphere and the mixture was refluxed with heating for five minutes. After cooling to room temperature, two drops of chlorotrimethylsilane was added to the reaction mixture. The mixture was stirred for 15 minutes. Next, (1S)-2,3,4,6-tetra-O-acetyl-1,5-anhydro-1-[5-(bromomethyl)-2-ethoxyphenyl]-D-glucitol (1.4 g) was added to the reaction mixture and the mixture was refluxed with heating for one hour. After cooling to room temperature, tetrakistriphenylphosphine palladium (0) (0.27 g) and methyl 2-chloroazulene-1-carboxylate (0.28 g) were added to the reaction mixture. The mixture was refluxed with heating for six hours. After cooling to room temperature, the reaction mixture was poured into 10% aqueous solution of hydrochloric acid under cooling with ice. The mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated. The residue was purified by silica gel column chromatography (n-hexane-ethyl acetate) to obtain methyl 2-(4-ethoxy-3-[(2S,3S,4R,5R,6R)-3,4,5-tris(acetyloxy)-6-[(acetyloxy)methyl]tetrahydro-2H-pyran-2-yl]benzyl)azulene-1-carboxylate (0.58 g).

Provenance & Evidence