Hydrochloric Acid → 3,3-Bis(((1,1-dimethylethyl)dimethylsilyl)oxymethyl)cyclobutanone-O-methyl oxime

Beteiligte Stoffe

Reaktionsschritte

3,3-Bis(hydroxymethyl)-1,1-dimethoxycyclobutane (1.35 g, 7.65 mmol) from Step A and 3.8 mL of 2M aqueous hydrochloric acid solution were added to 60 mL of THF and the reaction mixture was stirred at ambient temperature for 0.5 h, under a nitrogen atmosphere. The reaction mixture was neutralized by the addition of a strongly basic hydroxide resin then filtered and concentrated in vacuo. The residue was washed with THF and dissolved in 30 mL of anhydrous pyridine. To this solution was added 767 mg (9.2 mmol) of methoxylamine hydrochloride and the resultant solution was stirred for ~20 h at ambient temperature, under a nitrogen atmosphere. t-Butyldimethylsilyl chloride (3.5 g, 23 mmol) and 60 mL of anhydrous pyridine were then added and stirring continued overnight. The bulk of the solvent was evaporated in vacuo at 35°-40° C. and the concentrate dissolved in 200 mL of methylene chloride. The methylene chloride solution was washed with 100 mL of water, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified on a 1.5×50 cm silica gel column eluted @ 5 psi with 200 mL of hexane, followed by 200 mL of 2% acetone in hexane, followed by 200 mL of 3% acetone in hexane, followed by 200 mL of 4% acetone in hexane and finally 200 mL of 10% acetone in hexane, to give 583 mg (20% yield) of the title compound; MS DCI-NH3M/Z: 388 (M+H)+ ; 1H NMR (CDCl3) δ 0.04 (s, 12H), 0.87 (s, 18H), 2.61 (d, 4H), 3.58 (s, 4H), 3.82 (s, 3H).

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