Hydrochloric Acid → Ethyl 4-Hydroxy-4-[3,4-dimethoxy-2-(1-methylethyl)phenyl]-3-methylbut-2-enoate

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Reaction Conditions

Reaction Steps

Compound 7 (10.0 g, 38.6 mmol) and ethyl bromide (0.60 g, 5.5mmol) were added to magnesium turnings (1.20 g, 49.4 mg atom) in 100 mL of dry THF in a 520 mL round bottom flask equipped with a reflux condenser and magnetic stirrer. The mixture was refluxed with stirring under a static nitrogen atmosphere for 1 h. The reaction mixture was cooled to 0° C. and 7a (6.90 g, 48.5mmol) in 25 mL of dry THF at 0° C. was added. The mixture was stirred at ambient temp for 1 h and poured into 100 g of ice and 25 ml of 6M HCl. The organic layer was extracted into ether and the ether was washed with water and brine and dried over MgSO4. The ether was evaporated and the byproducts distilled bulb to bulb (120° C./1 torr) to leave 9.8 g (30.4 mmol, 79%) of 8 as a residual oil: IR 3440 (alcohol), 1722 (ester), 1655 (alkene) cm-1 ; 1H NMR δ1.31 (t, J=7.1 Hz, 3H), 1.37 (d, J=7.0 Hz, 6H), 1.99 (s, 3H), 3.40 (br s, 1H), 3.75-3.85 (m, 1H), 3.847 (s, 3H), 3.853 (s, 3H), 4.19 (q, J+7.1 Hz, 2H), 5.39 (s, 1H), 6.26 (s, 1H), 6.75 (d, J=8.6 Hz, 1H), 6.94 (d, J=7.1 Hz, 1H). Anal. (C18H26O5) C,H.

Provenance & Evidence