反应详情

A solution of (E) Methyl 2-diazo-4-phenyl-3-butenoate (0.26 g, 1.3 mmol) in dry pentane (20 mL) is added dropwise to a stirred solution of Rh2 (TBSP)4 (0.0195 g, 13.5 mmol) and cis-1,3-pentadiene (0.45 g, 6.7 mmol) in dry pentane (50 mL) under an argon atmosphere at room temperature. After stirring for 2 hours the solvent is removed under reduced pressure. Purification by silica gel column chromatography (1/99; diethyl ether/petroleum ether, Rf =0.05) gave the product as a yellow oil (0.25 g, 79%). IR (neat) 3025.0, 2952.4, 2872.3, 1712.2, 1652.4, 1455.8, 1435.7, 1240.3; 1H NMR (CDCl3)d 7.43-7.21 (m, 5H), 7.05 (d, 1H, J=5.1 Hz), 5.82 (dp, 1H, J=5.7, 2.0 Hz), 5.58 (dd, 1H, J=5.3, 3.8 Hz), 3.74 (s, 3H), 3.60 (dd, 1H, J=9.8, 5.2 Hz), 3.29 (d, 1H, J=5.7 Hz), 2.90-5.70 (m, 1H), 0.83 (d, 3H, J=7.0 Hz); 13C NMR (CDCl3)d 168.0, 146.3, 143.5, 136.7, 131.9, 128.6, 128.2, 126.7, 126.6, 51.9, 51.0, 36.3, 25.3, 20.8; MS m/z (relative intensity) 242 (100), 91 (70); HRMS calcd for C16H18O2 : 242.1307. Found: 242.1314.

1. customis removed under reduced pressure
2. customPurification by silica gel column chromatography (1/99; diethyl ether/petroleum ether, Rf =0.05)