Ethyl acetate 2 -hydroxy-4 -methoxyacetophenone

Et2Zn) (20 (iL, 0.02 mmol, 1.0 M in hexanes) was added at the same temperature. After stirring for 30 minutes at — 20 °C, a solution of 2-hydroxy-2 -methoxyacetophenone (322.3 mg, 2.0 mmol) in tetrahydrofuran (4.7 mL) was added. The resulting mixture was cooled to —30 °C and hydrocinnamaldehyde (1.0 mmol) was added and stirred at the same temperature. The stirring was continued for 20 hours at this temperature (TLC hexane/ethyl acetate = 2/1, iyw-diol R< 0.44, anti-diol Rf = 0.26) and quenched by addition of 1 M hydrochloric acid (2mL). The mixture was extracted with ethyl acetate (x 3) and the combined organic layers were washed with brine and dried over sodium sulfate. Evaporation of solvent gave a crude mixture of the aldol products. 

COCH3 - Preparation by catalytic hydrogenolysis of 4-(benzyloxy)-2-hydroxy-3-methoxyacetophenone in the presence of 5% Pd/C in ethyl acetate [1989,2817], (90%) [2817]. 

Obtained by reaction of cupric bromide with 2-hydroxy-4-methoxyacetophenone, in refluxing chloroform-ethyl acetate mixture [4391,4413], (quantitative yield) [4391] according to [4390], (62%) [4483] or in refluxing dioxane (44%) [4484], (10%) [4411]. 

Preparation by reaction of cupric bromide on 4-hydroxy-3-methoxyacetophenone in refluxing chloroform-ethyl acetate mixture (quantitative yield) [4391]. 

COCH2Br - Preparation by reaction of bromine on 4-ethyl-2-hydroxy-5-methoxyacetophenone in acetic acid at C2H5 r r.t. (59%) [4516]. 

Preparation by reaction of sulfuryl chloride on 2-hydroxy-6-methoxyacetophenone in refluxing ethyl ether (93%) or in refluxing acetic acid (66%) [2021],... 

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