反应详情

To a solution of (1R,10R,11S,16S)-4,6-dimethoxy-1,11,15,15-tetramethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-2,4,6-triene (Compound No. 42) (0.69 g, 1.9 mmol) in CH2Cl2 (20 mL), cooled to 0° C., and a BBr3 solution (7.3 mL, 1 M in CH2Cl2, 7.3 mmol) was added dropwise. The ice bath was removed and the reaction was stirred at room temperature for 6 h. The reaction was quenched with MeOH (20 mL) and concentrated. The quenching and concentration steps were repeated six times. Purification by column chromatography on silica gel (Hexanes/EtOAc, 4:1) gave (1R,10R,11S,16S)-1,11,15,15-tetramethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-2,4,6-triene-4,6-diol (Compound No. 43) (0.42 g, 66%) as a pale pink solid. 1H NMR (CDCl3): δ 6.28 (d, 1H), 6.17 (d, 1H), 5.48 (br s, 1H), 4.40 (m, 1H), 4.25 (br s, 1H), 4.15 (t, 1H), 2.20 (m, 1H), 1.80-1.35 (m, 7H), 1.28 (s, 3H), 1.25-1.00 (m, 4H), 0.92 (s, 3H), 0.88 (s, 3H), 0.82 (s, 3H). MS m/z 331 (C21H30O3+H+).

1. customThe ice bath was removed
2. customThe reaction was quenched with MeOH (20 mL)
3. concentrationconcentrated
4. concentrationThe quenching and concentration steps
5. customPurification by column chromatography on silica gel (Hexanes/EtOAc, 4:1)