反应详情

温度

-10 °C

A flask containing 1.15 g of acetic anhydride was cooled to −10° C. with a salt-ice bath, and 3.1 g of 4 was added with magnetic stirring under an N2 atmosphere. After 10-15 min, 25 mL of concentrated H2SO4 was added. The reaction mixture was allowed to stir for an additional 10 min, after which it was diluted with 40 mL of ether and 10 mL of H2O. The mixture was extracted three times with 15 mL of saturated aqueous sodium bicarbonate and once with 10 mL of saturated aqueous NaCl. The ether layer was dried over anhydrous MgSO4, and the solvent was removed by rotary evaporation to yield 1.40 g of a mixture of stereoisomers of the nitro acetate 5. 1H NMR δ (ppm) 5.4 (br m, CHOCOCH3), 5.2 (t, CH3C(CH3)═CH and CH2C(CH3)═CH), 4.4 (m, CHNO2), 2.1 (s, CH3CO2), 2.0 (m, C═CHCH2CH2C(CH3)═CHCH2), 1.6-1.7 (all s, CH3C(CH3)═CHCH2CH2CCH3), 1.5 (d, CH3CHNO2), 1.2-1.5 (m, CH2CH(CH3)CH2), 0.9 (d, CH2CH(CH3)CH2).

1. stirringto stir for an additional 10 min
2. extractionThe mixture was extracted three times with 15 mL of saturated aqueous sodium bicarbonate
3. dry with materialThe ether layer was dried over anhydrous MgSO4
4. customthe solvent was removed by rotary evaporation