反应详情

Metallic sodium (15 g, 230 mmol) was dissolved in dry ethanol (250 mL) with cooling in an ice bath, under nitrogen, and diethyl allylmalonate (Lancaster Synthesis, Windham, Mass.) (105 g, 525 mmol) in absolute ethanol (50 mL) was added dropwise under nitrogen. The mixture was stirred at room temperature for 1 h. and 2-bromoethyl methyl ether (87.57 g, 630 mmol) in absolute ethanol (50 mL) was then added dropwise. The mixture was heated at reflux for 3 h and then cooled to room temperature. The precipitate solid was filtered and washed with ethanol (2×100 mL). The residue obtained upon concentration of the filtrate was diluted with water (1 L). The mixture was extracted with ether (2×150 mL), dried over MgSO4 and concentrated to give the diester ether 2 (118 g, 87%) as a viscous liquid. IR (KBr) υmax 3069, 2971, 2927, 1734, 1640, 1459, 1443, 1382, 1361, 1284, 1223, 1196, 1119, 1077, 1031, 922, 856 cm−1: 1HNMR (CDCl3) δ1.24 t, J=7.0 Hz, 6 H), 2.17 (t, J=6.4 Hz, 2 H), 2.68 (d, J=7.1 Hz, 2 H), 3.2 (s, 3 H), 3.41 (t, J=6.5 Hz, 2 H), 4.17 (dis q, 4 H), 5.04-5.12 (m, 2 H), 5.63-5.79 (m, 1 H); 13CNMR (CDCl3) δ13.98, 32.05, 37.31, 55.08, 58.52, 61.13, 68.34, 118.93, 132.49, 170.17; mass spectrum (EI), m/z (rel itensity) 259 (M++1.16), 227 (20), 213 (19), 200 (37), 185 (13), 167 (17), 154 (25), 153 (65), 139 (38), 125 (25), 108 (100), 81 (30), 79 (31), 67 (23), 59 (23), 53 (23).

1. temperaturewith cooling in an ice bath, under nitrogen
2. temperatureThe mixture was heated
3. temperatureat reflux for 3 h
4. temperaturecooled to room temperature
5. filtrationThe precipitate solid was filtered
6. washwashed with ethanol (2×100 mL)
7. customThe residue obtained upon concentration of the filtrate
8. extractionThe mixture was extracted with ether (2×150 mL)
9. dry with materialdried over MgSO4
10. concentrationconcentrated