hexyl 2-hydroxy-4-methylsulfanylbutanoate

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

Procedure: To a solution of hexyl 2-hydroxy-4-(methylthio)butanoate (5.03 g, 21.46 mmol) in dichloromethane at 0° C. was added m-chloroperoxybenzoic acid (mCPBA) portionwise over 20 min. The resulting mixture was allowed to warm to room temperature with stirring overnight. The reaction was washed with saturated sodium bicarbonate (3×100 mL), 1N HCl (1×80 mL), and brine (1×80 mL). The organic layer was dried over magnesium sulfate, filtered and evaporated to give ˜6 g of a crude oil. The oil was purified by silica gel chromatography with 0-6% methanol/dichloromethane to give an oil (4.10 g, 76%). 1H NMR (500 MHz, chloroform-d) δ ppm 0.89 (t, J=6.68 Hz, 3 H) 1.25-1.39 (m, 6 H) 1.67 (quin, J=6.99 Hz, 2 H) 2.05-2.17 (m, 1 H) 2.32-2.42 (m, 1 H) 2.56-2.63 (m, 3 H) 2.72-2.97 (m, 2 H) 3.34-3.44 (m, 1 H) 4.15-4.24 (m, 2 H) 4.26-4.36 (m, 1 H). m/z 251 (MH+). The reaction was washed with saturated sodium bicarbonate (3×100 mL), 1N HCl (1×80 mL), and brine (1×80 mL) The organic layer was dried over magnesium sulfate filtered evaporated to give ˜6 g of a crude oil The oil was purified by silica gel chromatography with 0-6% methanol/dichloromethane

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

Procedure: To a 4 neck 1 L round bottom flask fitted with a reflux condenser, dean stark trap, thermocouple, and mechanical overhead stirrer was added 2-hydroxy-4-(methylthio)butanoic acid (100 g, 666 mmol, obtained for example by stirring Alimet over activated charcoal, filtering and concentrating in a rotovap), 1-hexanol (125.4 mL, 999 mmol), sodium hydrogen sulfate (1.60 g, 13.32 mmol), and toluene (500 mL). The reaction was heated to reflux with removal of water (20 mL) during the course of about 5.5 hours and the reaction was monitored by GC analysis. The reaction was cooled to room temperature overnight and the organic layer was washed with saturated NaHCO3 (1×250 mL), DI water (1×250 mL) and brine (2×250 mL), dried over sodium sulfate, filtered and evaporated to give a brown oil (253.3 g). The oil was purified by kugelrohr distillation at 100° C. and 0.1 Torr vacuum to give a colorless oil (100.0 g, 64.1%). m/z 257 (MNa+). To a 4 neck 1 L round bottom flask fitted with a reflux condenser, dean stark trap filtering The reaction was heated the organic layer was washed with saturated NaHCO3 (1×250 mL), DI water (1×250 mL) and brine (2×250 mL) dried over sodium sulfate filtered evaporated