tert-Butyl methyl ether → (4R,5R)-3-Methoxyimino-4,5-dimethyl-heptanoic Acid Ethyl Ester

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Reaction Steps

(4R,5R)-4,5-Dimethyl-3-oxo-heptanoic acid ethyl ester (21.23 g, 106 mmol) was dissolved in 200 mL of EtOH and added to 10.6 g (127 mmol) of methoxylamine-HCl and 10.6 g (127 mmol) of sodium acetate solids. The slurry was stirred at room temperature for 48 hours. MTBE (200 mL) and 100 mL of water were added, and the resulting phases were separated. The organic phase was washed with 100 mL of water and was evaporated to yield a two-phase mixture. Hexanes (100 mL) were added and the phases were separated. The aqueous phase was extracted with 50 mL of hexanes and the combined organic phases were washed with 50 mL of water, dried over magnesium sulfate, and evaporated to give 21.24 g (87.4% yield) of the titled compound as a clear yellow oil: 1H NMR (CDCl3, 399.77 MHz) δ 0.84–0.88 (m, 6H), 1.07 (d, J=7.1 Hz, 3H), 1.24 (t, J=7.1 Hz, 3H), 1.4–1.6 (m, 2H), 2.24 (m, 1H), 3.08 (d, J=15.8 Hz, 1H), 3.19 (d, J=15.8 Hz, 1H), 3.80 (s, 3H), 4.10–4.2 (m, 3H). Low resolution mass spec: nominal m/e calc'd for C12H23NO3 (M+H)+: 230. Found: m/e 230.

Provenance & Evidence