反应详情

温度

2.5 °C

Step-III: To a stirred solution of (3aS,5S,6R,6aS)-5-hydroxymethyl-2,2-dimethyl-tetrahydro-furo[2,3-d][1,3]dioxol-6-ol (30 g, 157 mmol) in acetone (450 ml) and water (150 ml) was added sodium bicarbonate (39.8 g, 473 mmol), sodium bromide (3.25 g, 31 mmol) and TEMPO (490 mg, 3.1 mmol) at 20° C. The mixture was cooled to 0-5° C. and solid trichloroisocyanuric acid (TCCA, 36.69 g, 157 mmol) was then added in portions. After stirring for 24 h at room temperature, methanol (25 ml) was added stirred for additional 1 h. The white suspension was formed. This was filtered, washed with acetone (50 ml×2). The volatiles were evaporated under reduced pressure. The aqueous layer was extracted with ethyl acetate (300 ml×3) and combined organic layers were concentrated to thick oily mixture with some solid residue. This was taken in acetone and filtered. The filtrate was concentrated to give 25 g of (3aS,5R,6S,6aS)-6-hydroxy-2,2-dimethyl-tetrahydro-furo[2,3-d][1,3]dioxole-5-carboxylic acid as a yellow solid. 1H NMR (400 MHz, CD3OD): δ 1.30 (s, 3H), 1.44 (s, 3H), 4.35 (d, J=2.8 Hz, 1H), 4.50 (d, J=2.0 Hz, 1H), 4.69 (d, J=3.6 Hz, 1H), 5.97 (d, J=3.2 Hz, 1H).

1. stirringstirred for additional 1 h
2. customThe white suspension was formed
3. filtrationThis was filtered
4. washwashed with acetone (50 ml×2)
5. customThe volatiles were evaporated under reduced pressure
6. extractionThe aqueous layer was extracted with ethyl acetate (300 ml×3)
7. concentrationwere concentrated to thick oily mixture with some solid residue
8. filtrationfiltered
9. concentrationThe filtrate was concentrated