反应详情

An aqueous solution of sodium hypochlorite (6.15% solution, 100 mL, 78.6 mmol) was added drop-wise to a solution of (1E)-2-[(1-cyclopropylpent-4-en-2-yl)oxy]-N-hydroxyethanimine (C68) (10 g, 55 mmol) and triethylamine (0.47 mL, 3.4 mmol) in dichloromethane (200 mL) that was immersed in a room temperature water bath. The rate of addition was adjusted to maintain the internal temperature of the reaction between 19.5° C. and 22.8° C. After completion of the addition, the reaction mixture was diluted with water (50 mL) and the aqueous layer was extracted with dichloromethane (3×50 mL). The combined organic layers were washed with saturated aqueous sodium chloride solution (50 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (Gradient: 0% to 20% ethyl acetate in petroleum ether) provided the product as a yellow oil. Yield: 3.8 g, 21 mmol, 39%. The indicated relative stereochemistry of compound C69 was assigned based on nuclear Overhauser enhancement studies, which revealed an interaction between the methine protons on carbons 3a and 5. LCMS m/z 182 [M+H+]. 1H NMR (400 MHz, CDCl3) δ 4.69 (d, J=13.6 Hz, 1H), 4.62 (dd, J=10.0, 8.0 Hz, 1H), 4.19 (d, J=12.8 Hz, 1H), 3.73-3.80 (m, 1H), 3.54-3.58 (m, 1H), 3.47-3.40 (m, 1H), 2.30 (dd, J=12.8, 6.4 Hz, 1H), 1.64 (quintet, J=6.8 Hz, 1H), 1.49 (q, J=11.7 Hz, 1H), 1.20-1.29 (m, 1H), 0.75-0.79 (m, 1H), 0.44-0.51 (m, 2H), 0.03-0.11 (m, 2H).

1. customwas immersed in a room temperature
2. additionThe rate of addition
3. temperatureto maintain
4. customthe internal temperature of the reaction between 19.5° C. and 22.8° C
5. additionAfter completion of the addition
6. extractionthe aqueous layer was extracted with dichloromethane (3×50 mL)
7. washThe combined organic layers were washed with saturated aqueous sodium chloride solution (50 mL)
8. dry with materialdried over sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated in vacuo