Hydrochloric Acid → 2-Butanone, 1-chloro-3-[(tetrahydro-2H-pyran-2-yl)oxy]-, (3R)-

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Reaction Steps

A mixture of 9.41 g (50 mmol) of methyl (R)-2-(3,4,5,6-tetrahydro-2H-pyran-2-yloxy)propionate, 8.74 g (75 mmol) of sodium chloroacetate, 7.53 g (75 mmol) of triethylamine, and 200 mL of THF was cooled in ice, and 199 g (300 mmol) of a 1.6 M solution of tert-butylmagnesium chloride was added dropwise thereto over a period of 2 hours. After the completion of the dropwise addition, the reaction was performed at room temperature for another 2 hours, and the reaction solution was cooled in ice again. Then, 50 mL of water was added thereto, and subsequently 100 mL of ethyl acetate was added. Furthermore, 10% hydrochloric acid was added in such a manner that the pH was 6.0. After stirring was performed at room temperature for 1 hour, the resulting organic layer was separated, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 9.81 g of a crude product. The resulting product was purified by column on silica gel to obtain 6.79 g of the title compound (yield: 73%). 1H-NMR (400 MHz, CDCl3) δ: 1.35 (d, 3H, J=6.6 Hz), 1.50-1.55 (m, 4H), 1.80-1.84 (m, 3H), 3.42-3.53 (m, 1H), 3.83-3.96 (m, 1H), 4.24 (q, 1H, J=6.8 Hz), 5.58 (m, 2H).

Provenance & Evidence