methyl (3R)-3-(4-hydroxyphenyl)hex-4-ynoate

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of (R)-3-(4-hydroxyphenyl)-hex-4-ynoic acid (25 g) obtained in Step 2 in methanol (125 mL) was added concentrated sulfuric acid (1.25 mL), followed by stirring the mixture at 80° C. for 2.5 hours. After cooling down to room temperature, water (100 mL) and sodium bicarbonate (4.14 g) were added to the reaction mixture, followed by concentration of the mixture. To the reaction mixture were added water and saturated aqueous sodium bicarbonate solution, followed by extraction with ethylacetate. The organic layer was washed with saturated brine, dried and concentrated. The residue was distilled azeotropically with toluene to give (R)-3-(4-hydroxyphenyl)-hex-4-ynoic acid methyl ester (28.5 g). After cooling down to room temperature followed by extraction with ethylacetate The organic layer was washed with saturated brine dried concentrated The residue was distilled azeotropically with toluene