ethyl 5-hydroxy-4,4-dimethylpentanoate

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

Procedure: To a solution of acid from Step 1 (2.92 g, 13.9 mmol) in a mixture of THF/DMF (5:1, 60 mL) was added isopropylchloroformate (2.71 mL, 20.9 mmol). After 20 h of stirring at room temperature, the solution was cooled to 0° C. and NaBH4 (1.06 g, 27.9 mmol) followed methanol (5 mL) was added to the solution. After 30 min of stirring, a saturated aqueous solution of ammonium chloride was added (20 mL) and followed by ethyl acetate (20 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (2×30 mL). The combined organic layers were washed with brine, dried with magnesium sulfate, filtered and the filtrate was concentrated in vacuo. The residue was purified by silica gel chromatography (hexanes/ethyl acetate 95:5 to 60:40). After evaporation at low temperature, ethyl 5-hydroxy-4,4-dimethyl-pentanoate (1.82 g, 75% yield) was obtained as a volatile colorless oil. the solution was cooled to 0° C. was added to the solution After 30 min of stirring The layers were separated the aqueous layer was extracted with ethyl acetate (2×30 mL) The combined organic layers were washed with brine dried with magnesium sulfate filtered the filtrate was concentrated in vacuo The residue was purified by silica gel chromatography (hexanes/ethyl acetate 95:5 to 60:40) After evaporation at low temperature