4,5-dimethylbenzene-1,2-diol

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 4,5-dimethylcatechol (663 mg) and 7-(4-fluorophenyl)-7-hydroxyheptanoic acid (1.15 g) in toluene (18 ml) was added sodium p-toluene sulfonate monohydride (455 ml) and the reaction was carried out at 100° C. for 20 hours. After cooling in air, the reaction mixture was extracted by addition of water and ethyl acetate. The organic layer was separated, washed in turn with water and saturated saline and dried with anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by subjecting it to silica gel column chromatography and eluting with ethyl acetate/hexane (1:7) to obtain 7-(4-fluorophenyl)-7-(2,3-dihydroxy-5,6-dimethylphenyl)heptanoic acid (530 mg) (Compound 57). The physical properties and spectrum data thereof are shown in Tables 3 and 4. After cooling in air the reaction mixture was extracted by addition of water and ethyl acetate The organic layer was separated washed in turn with water and saturated saline dried with anhydrous magnesium sulfate the solvent was distilled off under reduced pressure The residue was purified eluting with ethyl acetate/hexane (1:7)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 4,5-dimethylcatechol (663 mg) and 7-(4-fluorophenyl)-7-hydroxyheptanoic acid (1.15 g) in toluene (18 ml) was added sodium p-toluene sulfonate monohydride (455 ml) and the reaction was carried out at 100° C. for 20 hours. After cooling in air, the reaction mixture was extracted by addition of water and ethyl acetate. The organic layer was separated, washed in turn with water and saturated saline and dried with anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by subjecting it to silica gel column chromatography and eluting with ethyl acetate/hexane (1:7) to obtain 7-(4-fluorophenyl)-7-(2,3-dihydroxy-5,6-dimethylphenyl)heptanoic acid (530 mg) (Compound 57). The physical properties and spectrum data thereof are shown in Tables 3 and 4. After cooling in air the reaction mixture was extracted by addition of water and ethyl acetate The organic layer was separated washed in turn with water and saturated saline dried with anhydrous magnesium sulfate the solvent was distilled off under reduced pressure The residue was purified eluting with ethyl acetate/hexane (1:7)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 4,5-dimethylcatechol (663 mg) and 7-(4-fluorophenyl)-7-hydroxyheptanoic acid (1.15 g) in toluene (18 ml) was added sodium p-toluene sulfonate monohydride (455 ml) and the reaction was carried out at 100° C. for 20 hours. After cooling in air, the reaction mixture was extracted by addition of water and ethyl acetate. The organic layer was separated, washed in turn with water and saturated saline and dried with anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by subjecting it to silica gel column chromatography and eluting with ethyl acetate/hexane (1:7) to obtain 7-(4-fluorophenyl)-7-(2,3-dihydroxy-5,6-dimethylphenyl)heptanoic acid (530 mg) (Compound 57). The physical properties and spectrum data thereof are shown in Tables 3 and 4. After cooling in air the reaction mixture was extracted by addition of water and ethyl acetate The organic layer was separated washed in turn with water and saturated saline dried with anhydrous magnesium sulfate the solvent was distilled off under reduced pressure The residue was purified eluting with ethyl acetate/hexane (1:7)

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 86 g of ethyl 2,3-dibromopropionate was added, over a 15-minute period, to a stirred mixture of 41 g of 6A, 97 g of potassium carbonate and 300 ml of acetone. The temperature of the mixture rose to 60° C. The mixture was refluxed for 19 hours, cooled to 30° C. and filtered. The solvent was evaporated from the filtrate under reduced pressure. The residue was recrystallized from hexane to give 6, mp: 71°-72° C. rose to 60° C The mixture was refluxed for 19 hours filtered The solvent was evaporated from the filtrate under reduced pressure The residue was recrystallized from hexane to give 6, mp: 71°-72° C.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 53 g of 4,5-dimethylveratrol (prepared by the method of Bruce, et al., J. Chem. Soc., 1956, 3824-29) was mixed with 200 ml of 48% hydrobromic acid. The mixture was stirred at reflux temperature, in a nitrogen atmosphere, for 4.5 hours. The crude mixture was heated with 200 ml of toluene. The toluene phase was separated and cooled, to give 4,5-dimethylcatechol (6A), as a solid, mp: 86°-87° C. at reflux temperature The toluene phase was separated cooled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred solution of 4,5-dimethylcatechol (7.0 g.) in dry acetone (45 ml.) was heated under reflux, then potassium carbonate (5 g.) was added followed by the dropwise addition of ethyl dibromopropionate (3.5 g.). The addition procedure was repeated a further three times over 11/4 hours then the reaction was stirred under reflux for a further 33/4 hours. After cooling, the mixture was filtered, the solids washed well with acetone then the combined filtrate concentrated in vacuo. Water (35 ml.) was added, the resulting solid collected, washed with petrol then taken up in ether. The ethereal solution was washed with water, dried (Na2SO4) and evaporated in vacuo to give ethyl 6,7-dimethyl-1,4-benzodioxan-2-carboxylate (10.17 g.), m.p. 70°-71° C. under reflux The addition procedure 4 hours under reflux for a further 33/4 hours After cooling the mixture was filtered the solids washed well with acetone the combined filtrate concentrated in vacuo Water (35 ml.) was added the resulting solid collected washed with petrol The ethereal solution was washed with water dried (Na2SO4) evaporated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 4,5-dimethylcatechol (663 mg) and 7-(4-fluorophenyl)-7-hydroxyheptanoic acid (1.15 g) in toluene (18 ml) was added sodium p-toluene sulfonate monohydride (455 ml) and the reaction was carried out at 100° C. for 20 hours. After cooling in air, the reaction mixture was extracted by addition of water and ethyl acetate. The organic layer was separated, washed in turn with water and saturated saline and dried with anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by subjecting it to silica gel column chromatography and eluting with ethyl acetate/hexane (1:7) to obtain 7-(4-fluorophenyl)-7-(2,3-dihydroxy-5,6-dimethylphenyl)heptanoic acid (530 mg) (Compound 57). The physical properties and spectrum data thereof are shown in Tables 3 and 4. After cooling in air the reaction mixture was extracted by addition of water and ethyl acetate The organic layer was separated washed in turn with water and saturated saline dried with anhydrous magnesium sulfate the solvent was distilled off under reduced pressure The residue was purified eluting with ethyl acetate/hexane (1:7)

Conditions: temp:0.00; pressure:0.00; stir: