反应详情

To a solution of 4-(2-methoxy-2-oxoethyl)benzoic acid (0.87 g, 4.48 mmol) in methylene chloride (5 mL) was condensed isobutylene (approximately 20 mL) at −78° C. The solution was treated with 0.5 mL concentrated sulfuric acid and the solution was sealed in a stainless steel bomb and allowed to warm to ambient temperature for 6 hours. The solution was recooled to −78° C. and opened. The reaction was partitioned between 0.1M sodium hydroxide solution and diethyl ether. The organics were dried over sodium sulfate, filtered and evaporated. Purification by flash chromatography (0-35% ethyl acetate/hexanes) gave tert-butyl 4-(2-methoxy-2-oxoethyl)benzoate as a clear oil. 1H NMR (600 MHz, DMSO-d6) δ 7.81 (d, J=8.21 Hz, 2H), 7.35 (d, J=8.51 Hz, 2H), 3.75 (s, 2H), 3.56 (s, 3H), 1.51 (s, 9H); ESIMS calcd 251.1 (M++H), found 251.0 (M++H).

1. customwas recooled to −78° C.
2. customThe reaction was partitioned between 0.1M sodium hydroxide solution and diethyl ether
3. dry with materialThe organics were dried over sodium sulfate
4. filtrationfiltered
5. customevaporated
6. customPurification by flash chromatography (0-35% ethyl acetate/hexanes)