反应详情

To (E)-(5S,6S,7S,8S)-9-tert-Butoxy-5,7-dimethoxy-6,8-dimethyl-nona-1,3-diene (1.3 g, 4.2 mmol) in anhydrous methanol (10 ml) at room temperature and under an atmosphere of nitrogen was added sodium methoxide (30% wt in MeOH, 3.7 ml, 20.8 mmol). The reaction was stirred overnight. A further amount of sodium methoxide (30% wt in MeOH, 3.7 ml, 20.8 mmol) was added and the reaction was stirred for a further 1 hour. The reaction was quenched with saturated ammonium chloride and extracted with dichloromethane (3×). The combined organic layers were dried by passing through a hydrophobic frit and concentrated in vacuo. The product was purified by flash chromatography (SiO2, iHex/EtOAc, 10:1 then 2:1) to afford 2.0 g (100%) as a clear oil. 1H NMR (300 MHz, CDCl3) δ 6.40 (dt, J=16.8 Hz, 10.4 Hz, 10.2 Hz, 1H), 6.23 (dd, J=15.2 Hz, 10.4 Hz, 1H), 5.46 (dd, J=15.2 Hz, 8.4 Hz, 1H), 5.26 (dd, J=17.0 Hz, 1.6 Hz, 1H), 5.14 (dd, J=10.2 Hz, 1.6 Hz, 1H), 3.77-3.53 (m, 3H), 3.51 (s, 3H), 3.42 (t, J=9.3 Hz, 1H), 3.27 (s, 3H), 2.75 (dd, J=8.4 Hz, 3.1 Hz, 1H), 1.91 (m, 1H), 1.72 (m, 1H), 0.85 (d, J=7.1 Hz, 3H), 0.80 (d, J=7.1 Hz, 3H).

1. stirringthe reaction was stirred for a further 1 hour
2. customThe reaction was quenched with saturated ammonium chloride
3. extractionextracted with dichloromethane (3×)
4. customThe combined organic layers were dried
5. concentrationconcentrated in vacuo
6. customThe product was purified by flash chromatography (SiO2, iHex/EtOAc, 10:1
7. custom2:1) to afford 2.0 g (100%) as a clear oil