Hydrochloric Acid → (E)-(2R,3R,4S,5S)-3,5-Dimethoxy-2,4-dimethyl-nona-6,8-dienoic acid

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Reaction Steps

To (E)-(2R,3R,4S,5S)-3,5-Dimethoxy-2,4-dimethyl-nona-6,8-dienal (1.2 g, 5.3 mmol) in tert-butanol (24 ml) and 2-methyl-2-butene (5.6 ml, 53.1 mmol) at room temperature, was added a solution of sodium chlorite (2.4 g, 26.5 mmol) and sodium dihydrogenphosphate (1.5 g, 10.6 mmol) in water (5 ml). The reaction was stirred vigorously for 1.5 hours, after which brine (10 ml) was added and the reaction acidified to pH5 with 2M hydrochloric acid. The reaction was extracted with dichloromethane (3×), the organics dried through a hydrophobic frit and concentrated in vacuo. The oily residue was left on a vacuum pump overnight to afford the product 3c as an orange solid (1.02 g, 79%). 1H NMR (300 MHz, CDCl3) δ 6.39 (dt, J=16.7 Hz, 10.3 Hz, 10.0 Hz, 1H), 6.23 (dd, J=14.9 Hz, 10.5 Hz, 1H), 5.45 (dd, J=14.9 Hz, 8.7 Hz, 1H), 5.26 (d, J=16.3 Hz, 1H), 5.14 (d, J=10.3 Hz, 1H), 3.91 (dd, J=9.4 Hz, 1.8 Hz, 1H), 3.46 (s, 3H), 3.43 (m, 1H), 3.26 (s, 3H), 2.67 (m, 1H), 1.71 (m, 1H), 1.13 (d, J=7.1 Hz, 3H), 0.78 (d, J=7.1 Hz, 3H).

Provenance & Evidence