反应详情

温度

0 °C

To a stirring solution of ethyl-4-(3-benzyloxy 4-propoxy-5-Iodophenyl)-4-oxo-1-butanoate (15.8 g, 0.031 ml) in ethanol (80 ml) at 0° C., was added sodium borohydride (0.90 g, 0.023 mol) slowly. The reaction mixture stirred for 10-15 mins at 0° C. The ethanol was removed and water was added and extracted with ethyl acetate (300 ml) dried, filtered and concentrated. The crude containing hydroxyester 6 and lactone 7 were purified on silica gel column using (1:5) EtoAc:light petroleum. The mixture was dissolved in dichloromethane (60 ml); to it PTSA (catalytic, 680 mg) was added at 0° C. and stirred at room temperature over night under nitrogen atmosphere. The dichloromethane solution was washed with water and aqueous NaHCO3 (50 ml), dried (Na2SO4), filtered and concentrated. The crude product was purified on silica gel column using EtOAc: light petroleum (1:5) to give 4-(3-benzyloxy-4-propoxy-5-Iodophenyl) butyrolactone (11.4 g, 79%). TLC: Ethyl acetate:light petroleum (1:3), Rf=0.25; 1H NMR: δ 1.03 (t, J=7.90 Hz, 3H), 1.75-1.90 (m, 2H), 2.0-2.3 (m, 1H), 2.45-2.65 (m,3H), 3.96 (t, J=6.04 Hz, 2H), 5.08 (s, 2H), 5.35 (t, J=6.97 Hz, 1H), 6.88 (d, J=1.62 Hz, 1H), 7.28 (d, J=1.62 Hz, 1H), 7.30-7.40 (m, 5H); EI Mass: 452 (M+), IR (neat): 3070, 2960, 2895, 1760, 1600, 1585 cm−1

1. customThe ethanol was removed
2. additionwater was added
3. extractionextracted with ethyl acetate (300 ml)
4. customdried
5. filtrationfiltered
6. concentrationconcentrated
7. additionThe crude containing hydroxyester 6 and lactone 7
8. customwere purified on silica gel column
9. dissolutionThe mixture was dissolved in dichloromethane (60 ml)
10. additionto it PTSA (catalytic, 680 mg) was added at 0° C.
11. stirringstirred at room temperature over night under nitrogen atmosphere
12. washThe dichloromethane solution was washed with water and aqueous NaHCO3 (50 ml)
13. dry with materialdried (Na2SO4)
14. filtrationfiltered
15. concentrationconcentrated
16. customThe crude product was purified on silica gel column