tert-butyl (3R,5R)-6-cyano-3,5-dihydroxyhexanoate

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

Procedure: A solution of tert-butyl (5R)-6-cyano-5-hydroxy-3-oxohexanoate (10 g, 0.044 mol) in THF (60 mL) was stirred under nitrogen and methanol (20 mL) was added. The reaction mixture was stirred for 15 min. Ti(IV)isopropoxide (12.5 g, 0.044 mol) was added and stirred for 30 min. at room temperature. After cooling the reaction mixture to −50° C. to −55° C., sodium borohydride (1.67 g, 0.044 mol) was added in 4 portions maintaining the temperature between −50° C. and −55° C. The resulting mixture was stirred for 1 h at the same temperature. After warming the reaction mixture to RT, it was concentrated to a residue under vacuum at about 45° C. Methanol (60 mL) was added and the resulting mixture was concentrated. The resulting residue was cooled to RT, water (50 mL) was added and the resulting aqueous mixture was extracted with ethyl acetate (100 mL×2). The combined organic layer was washed with saturated ammonium chloride solution (2×50 mL), water (50 mL) and brine solution (50 mL), and concentrated to obtain the title compound. Yield: 7.5 g. stirred for 30 min. at room temperature After cooling the reaction mixture to −50° C. to −55° C. maintaining the temperature between −50° C. and −55° C The resulting mixture was stirred for 1 h at the same temperature it was concentrated to a residue under vacuum at about 45° C Methanol (60 mL) was added the resulting mixture was concentrated The resulting residue was cooled to RT water (50 mL) was added the resulting aqueous mixture was extracted with ethyl acetate (100 mL×2) The combined organic layer was washed with saturated ammonium chloride solution (2×50 mL), water (50 mL) and brine solution (50 mL) concentrated

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

Procedure: A solution of tert-butyl (5R)-6-cyano-5-hydroxy-3-oxohexanoate (10 g, 0.044 mol) in THF (60 mL) was stirred under nitrogen and methanol (20 mL) was added. The reaction mixture was stirred for 15 min. and cooled to −50° C. to −55° C. CeCl3.7H2O (16.4 g, 0.044 mol) was added and stirred for 30 min., maintaining the temperature between −50 and −55° C. Sodium borohydride (2.5 g, 0.066 mol) was added in 6 portions maintaining the temperature between −70 and −90° C. The resulting mixture was stirred for 1 h at the same temperature. After warming the reaction mixture to RT, it was concentrated to a residue under vacuum at about 45° C. Methanol (60 mL) was added and the resulting mixture was concentrated. The resulting residue was cooled to RT, water (50 mL) was added and the resulting aqueous mixture was extracted with ethyl acetate (100 mL×2). The combined organic layer was washed with brine solution (50 mL), and concentrated to obtain title compound. Yield: 5 g. cooled to −50° C. to −55° C stirred for 30 min. maintaining the temperature between −50 and −55° C maintaining the temperature between −70 and −90° C The resulting mixture was stirred for 1 h at the same temperature it was concentrated to a residue under vacuum at about 45° C Methanol (60 mL) was added the resulting mixture was concentrated The resulting residue was cooled to RT water (50 mL) was added the resulting aqueous mixture was extracted with ethyl acetate (100 mL×2) The combined organic layer was washed with brine solution (50 mL) concentrated

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

Procedure: A solution of tert-butyl (5R)-6-cyano-5-hydroxy-3-oxohexanoate (10 g, 0.044 mol) in THF (60 mL) was stirred under nitrogen and methanol (20 mL) was added. The reaction mixture was stirred for 15 min. and cooled to −50° C. to −55° C. Anhydrous CeCl3 (10.8 g, 0.044 mol) was added and stirred for 30 min., maintaining the temperature between −50 and −55° C. Sodium borohydride (2.5 g, 0.066 mol) was added in 6 portions maintaining the temperature between −70 and −90° C. The resulting mixture was stirred for 1 h at the same temperature. After warming the reaction mixture to room temperature (RT), it was concentrated to a residue under vacuum at about 45° C. Methanol (60 mL) was added and the resulting mixture was concentrated. The resulting residue was cooled to RT, water (50 mL) was added and the resulting aqueous mixture was extracted with ethyl acetate (100 mL×2). The combined organic layer was washed with brine solution (50 mL), and concentrated to obtain the title compound. Yield: 9 g. cooled to −50° C. to −55° C stirred for 30 min. maintaining the temperature between −50 and −55° C maintaining the temperature between −70 and −90° C The resulting mixture was stirred for 1 h at the same temperature was concentrated to a residue under vacuum at about 45° C Methanol (60 mL) was added the resulting mixture was concentrated The resulting residue was cooled to RT water (50 mL) was added the resulting aqueous mixture was extracted with ethyl acetate (100 mL×2) The combined organic layer was washed with brine solution (50 mL) concentrated