反应详情

The cross metathesis of (±)-2-(but-3-enyl)oxirane (3.80 g, 38.7 mmol) with ethyl allyl ether (10.0 g, 116 mmol) was performed as described previously in Example 9.2, Step A to give (±)-2-(5-ethoxypent-3-enyl)oxirane as an inseparable mixture of olefin isomers (trans:cis=10:1) after silica gel chromatography. 1H NMR (400 MHz, CDCl3): trans isomer: δ 5.73 (1H, m), 5.63 (1H, m), 3.91 (2H, m), 3.48 (2H, q, J=7.0 Hz), 2.93 (1H, m), 2.75 (1H, dd, J=5.0, 2.7 Hz), 2.22 (2H, m), 1.63 (2H, m), 1.21 (3H, t, J=7.0 Hz). cis isomer: δ 5.62 (2H, m), 4.04 (2H, m), 3.48 (2H, q, J=7.0 Hz), 2.93 (1H, m), 2.75 (1H, m), 2.49 (1H, m), 2.22 (2H, m), 1.63 (2H, m), 1.22 (3H, t, J=7.0 Hz).