反应详情

To a solution of 2-(3-(2-hydroxy-1-methylethyl)-4-nitrophenyl)-2-phenyl-1,3-dioxane (18) (23.6 g; approx. 69 mmol) in ethanol (350 mL) was added water (70 mL) under vigorous stirring. Concentrated hydrochloric acid (about 12 N aqueous solution, 35 mL) was then added drop wise. The reaction mixture was stirred at ambient temperature for 4 hours, diluted with water and extracted with ethyl acetate. The organic phase was successively washed with an aqueous, saturated solution of NaHCO3 and with water. The organic phase was then concentrated in vacuo and seeded with crystals of the product 4f to provide a yellow solid. Finally, the powdered solid was washed with hexane and air dried to yield 17.83 g (62.5 mmol, 91%) of a yellow powder. 1H NMR (250 MHz, DMSO-d6) δ 7.91-7.52 (m, 8H, arom.), 4.75 (br. s., 1H, OH), 3.53 (d, 2H, α-CH2), 3.23 (sextet, 1H, β-CH), 1.24 (d, 3H, γ-CH3).

1. extractionextracted with ethyl acetate
2. washThe organic phase was successively washed with an aqueous, saturated solution of NaHCO3
3. concentrationThe organic phase was then concentrated in vacuo
4. customto provide a yellow solid
5. washFinally, the powdered solid was washed with hexane and air
6. customdried