反应详情

(1RS, 2RS, 3aSR, 8bRS)-1-azido-2-hydroxy-2,3,3a,8b-tetrahydro-1H-cyclopenta[b]benzofuran-5-carboxylic acid methyl ester (2) (2.5 g) was dissolved in anhydrous THF (40 ml) followed-by addition of a catalytic amount of p-toluenesulfonic acid and 2,3-dihydropyrane (1.64 ml) and stirring for 16 hours at room temperature. A saturated aqueous solution of sodium hydrogencarbonate (50 ml) was added to the reaction mixture followed by extraction with ethyl acetate (150 ml, 100 ml), combining of the organic layers, washing with water (50 ml) and saturated brine (50 ml) and concentration after drying with magnesium sulfate. The resulting residue was purified with column chromatography (silica gel: ethyl acetate/cyclohexane 1/10) to obtain the target confound (3.2 g, 98%).

1. extractionfollowed by extraction with ethyl acetate (150 ml, 100 ml)
2. washwashing with water (50 ml) and saturated brine (50 ml) and concentration
3. dry with materialafter drying with magnesium sulfate
4. customThe resulting residue was purified with column chromatography (silica gel: ethyl acetate/cyclohexane 1/10)
5. customto obtain the target confound (3.2 g, 98%)