反应详情

At 23° C., a flask containing (S)-2-(1-(1-chloro-3-methylnaphthalen-2-yl)-2-(trityloxy)ethoxy)-2-methylpropan-1-ol (1.31 g, 2.21 mmol) was charged with Ac2O (5.00 mL) immediately followed by pyridine (5.00 mL). 4-(N,N-dimethylamino)-pyridine (20 mg, 0.164 mmol) was added. After 1.5 h, the reaction was poured onto 50 mL of crushed ice and H2O. A white precipitate developed. EtOAc (50 mL) was added after several hours had passed. Solid NaHCO3 was added portionwise (bubbling) until the aq. layer had a pH of 9. The slurry was extracted with EtOAc (2×25 mL). The combined organic layers were washed with 1.0 M aq. CuSO4 monohydrate (3×25 mL) and H2O (25 mL). The final organic phase was dried over Na2SO4, filtered, and concentrated. The residue was treated with benzene and purified by flash column chromatography (silica gel, 0 to 100% ethyl acetate/hexanes) to give (S)-2-(1-(1-chloro-3-methylnaphthalen-2-yl)-2-(trityloxy)ethoxy)-2-methylpropyl acetate. 1H NMR (400 MHz, CDCl3) δ 8.25 (d, J=8.6 Hz, 1H), 7.68 (d, J=7.8 Hz, 1H), 7.52-7.41 (m, 9H), 7.26-7.16 (m, 9H), 5.99 (dd, J=8.2, 4.7 Hz, 1H), 4.02 (app. s, 2H), 3.55 (dd, J=8.6, 8.4 Hz, 1H), 3.12 (dd, J=9.8 Hz, 4.7 Hz, 1H), 2.52 (s, 3H), 1.86 (s, 3H), 1.32 (s, 3H), 1.15 (s, 3H).

1. custom(bubbling) until the aq. layer
2. extractionThe slurry was extracted with EtOAc (2×25 mL)
3. washThe combined organic layers were washed with 1.0 M aq. CuSO4 monohydrate (3×25 mL) and H2O (25 mL)
4. dry with materialThe final organic phase was dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. additionThe residue was treated with benzene
8. custompurified by flash column chromatography (silica gel, 0 to 100% ethyl acetate/hexanes)