Methyl morpholine oxide → (E)-(2R,3R,4S,5S)-3,5-Dimethoxy-2,4-dimethyl-nona-6,8-dienal

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Reaction Steps

To (E)-(2S,3S,4S,5S)-3,5-Dimethoxy-2,4-dimethyl-nona-6,8-dien-1-ol (1.3 g, 5.70 mmol) in anhydrous dichloromethane (58 ml) at room temperature and under an atmosphere of nitrogen was added activated 4A molecular sieves (1.3 g), N-methylmorpholine-N-oxide (2.0 g, 17.1 mmol) and TPAP (100 mg, 0.29 mmol). The reaction was stirred for 3 hours and filtered through a SiO2 pad, and the pad washed well with diethyl ether. The filtrate was concentrated in vacuo to afford the product as a clear oil (1.2 g, 93%). 1H NMR (300 MHz, CDCl3) δ 9.83 (d, J=2.7 Hz, 1H), 6.40 (dt, J=16.8 Hz, 10.2 Hz, 1H), 6.24 (dd, J=15.2 Hz, 10.6 Hz, 1H), 5.45 (dd, J=15.2 Hz, 8.8 Hz, 1H), 5.26 (dd, J=16.4 Hz, 1.3 Hz, 1H), 5.14 (dd, J=10.2 Hz, 1.6 Hz, 1H), 3.87 (dd, J=9.1 Hz, 2.4 Hz, 1H), 3.41 (m, 1H), 3.43 (s, 3H), 3.26 (s, 3H), 2.62 (m, 1H), 1.70 (m, 1H), 1.00 (d, J=7.1 Hz, 3H), 0.82 (d, J=7.1 Hz, 3H).

Provenance & Evidence