反应详情

A solution of 23 (1.10 g, 6.88 mmol) and (carbethoxymethylene)triphenylphosphorane (2.63 g, 7.56 mmol, 1.1 equiv) was refluxed in CH2Cl2 (8.2 mL) for 24 h. The solvent was removed at reduced pressure. The oily residue was chromatographed [silica, hexanes/diethyl ether (1:1)] to yield a pale yellow oil (1.31 g, 88%): 1H NMR δ 1.50-1.62 (m, 2H), 1.69-1.85 (m, 2H), 2.45-2.51 (m, 1H), 3.23-3.33 (m, 10H), 5.79 (d, J=16.1 Hz, 1H), 6.71 (dd, J=9.5 Hz, J2=16.1 Hz, 1H); 13C NMR δ 14.46, 34.42, 36.40, 58.79, 60.48, 70.42, 122.03, 152.01, 166.73; FAB-MS obsd 231.1596, calcd 231.1598 [(M+H)+, M=C12H22O4].

1. customThe solvent was removed at reduced pressure
2. customThe oily residue was chromatographed [silica, hexanes/diethyl ether (1:1)]