反应详情

温度

25 °C

To 60% sodium hydride (74 mg, 2.2 mmol) in toluene (10 mL) at 0° C. was added dropwise a solution of 5-vinylpyrrolidin-2-one (222 mg, 2.0 mmol) in toluene (5 mL) over a 5 min period. The cooling bath was removed and the solution was allowed to warm to 25° C. to ensure complete generation of the anion. To the anion at 25° C. was added dropwise a solution of (2R)-2-(2,4-di-t-butylphenyloxy)propanoyl chloride (16, 716 mg, 2.2 mmol) in toluene (5 mL) over a 5 min period. TLC indicated that the reaction was complete upon addition of the acid chloride (silica gel plates; hexane and ethyl acetate, 4:1). Water (30 mL) was added to the reaction mixture and the phases were separated. The aqueous phase was extracted with methylene chloride (1×25 mL). The combined organic phases were washed with a saturated aqeous sodium bicarbonate solution (1×50 mL) and dried (MgSO4). Concentration and purification by flash chromatography on silica gel (EM silica gel 60, 0.040-0.063 partical size, 230-400 Mesh, column size: 4.5 cm diameter×15 cm length) using hexane and ethyl acetate (19:1) afforded 360 mg (45%) of (5S)-N-((2R)-2-(2,4-di-t-butylphenyloxy)propanoyl)-5 -ethenylpyrrolidin-2-one (19a) as a thick oil: 1H NMR (CDCl3) δ1.28 (s, 9 H), 1.42 (s, 9 H), 1.77-1.80 (d, 3 H), 1.95-2.10 (m, 1 H), 2.23-2.33 (m, 1 H), 2.52-2.82 (m, 2 H), 4.91-4.97 (q, 1 H), 5.10-5.19 (m, 2 H), 5.80-5.90 (m, 1 H), 5.97-6.03 (m, 1 H), 6.49-6.53 (d, 1 H), 7.12-7.16 (d, 1 H), 7.35 (s, 1 H); 13C NMR (CDCl3) δ175.4, 172.9, 157.3, 153.4, 143.1, 137.2, 135.6, 124.3, 123.2, 115.8, 71.6, 57.9, 35.2, 34.2, 31.9, 31.4, 29.9, 24.3, 18.2; IR (neat) 2965 (vs), 1741 (vs), 1715 (vs), 1590 (s), 1230 (vs), 710 (w) cm-1.

1. customThe cooling bath was removed
2. customthe phases were separated
3. extractionThe aqueous phase was extracted with methylene chloride (1×25 mL)
4. washThe combined organic phases were washed with a saturated aqeous sodium bicarbonate solution (1×50 mL)
5. dry with materialdried (MgSO4)
6. concentrationConcentration and purification by flash chromatography on silica gel (EM silica gel 60, 0.040-0.063 partical size, 230-400 Mesh, column size: 4.5 cm diameter×15 cm length)