2-O-benzyl 1-O-tert-butyl (2S,3R)-3-hydroxypyrrolidine-1,2-dicarboxylate

反応条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: The title compound was prepared in a similar manner as described by L. Demange et al., Tetrahedron Letters 2001, 42, 651-653: To a solution of (2S,3R)-3-hydroxy-pyrrolidine-1,2-dicarboxylic acid 2-benzyl ester 1-tert-butyl ester (360 mg, 1.12 mmol) in CH2Cl2 (30 mL), cooled to −78° C., was added dropwise DAST (0.740 mL, 5.60 mmol). The reaction mixture was stirred at −78° C. for 5 h, and then was allowed to warm to RT and stirred overnight. After cooling to 0° C., the reaction was quenched with MeOH, followed by addition of aqueous NaHCO3 solution. Volatiles were removed under reduced pressure and the residue was taken up in EtOAc. The organics were washed with aqueous NaHCO3 (3×), water and brine, dried (Phase separator) and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 1:9) to give the title compound (99% purity by HPLC/215 nm). TLC Rf (EtOAc/c-hexane 1:4)=0.2; MS (LC/MS): 346 [M+Na]+, 268 [MH−tBu]+, 224 [MH−Boc]+; tR (HPLC conditions b): 5.01 min. The title compound was prepared in a similar manner to warm to RT stirred overnight After cooling to 0° C. the reaction was quenched with MeOH followed by addition of aqueous NaHCO3 solution Volatiles were removed under reduced pressure The organics were washed with aqueous NaHCO3 (3×), water and brine dried (Phase separator) concentrated in vacuo The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 1:9)

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of (2S,3S)-3-hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester [187039-57-2] (500 mg, 2.16 mmol) in MeOH (9.0 mL), cooled to 0° C., was added with stirring a solution of Cs2CO3 (704 mg, 2.162 mmol) in water (6.0 mL). The mixture was concentrated by rotary evaporation and the residue was suspended in DMF (17.0 mL). The suspension was cooled to 0° C., followed by addition of benzylbromide (0.514 mL, 4.32 mmol) and stirring overnight at RT. The reaction mixture was filtered, the filtrate was concentrated under reduced pressure and the residue was dissolved in EtOAc. The organics were washed with aqueous NaHCO3 (2×) and water (2×), dried (Phase separator) and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 2:3) to give the title compound as a white solid. MS (LC/MS): 665 [2M+Na]+, 266 [MH−tBu]+, 222 [MH−Boc]+; tR (HPLC conditions b): 4.18 min. was added The mixture was concentrated by rotary evaporation The reaction mixture was filtered the filtrate was concentrated under reduced pressure the residue was dissolved in EtOAc The organics were washed with aqueous NaHCO3 (2×) and water (2×) dried (Phase separator) concentrated in vacuo The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 2:3)

反応条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: The title compound was prepared in a similar manner as described by J. A. Hodges et al., J. Amer. Chem. Soc. 2005, 127, 15923-15932: To a solution of (2S,3R)-3-hydroxy-pyrrolidine-1,2-dicarboxylic acid 2-benzyl ester 1-tert-butyl ester (490 mg, 1.53 mmol) in CH2Cl2 (30 mL), cooled to −78° C., was added dropwise DAST (1.01 mL, 7.62 mmol). The reaction mixture was stirred at −78° C. for 5 h, and then was allowed to warm to RT and stirred overnight. After cooling to 0° C., the reaction was quenched with MeOH, followed by addition of aqueous NaHCO3 solution. Volatiles were removed under reduced pressure and the residue was taken up in EtOAc. The organics were washed with aqueous NaHCO3 (3×), water and brine, dried (Phase separator) and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 1:9) to give the title compound (89% purity by HPLC/215 nm). MS (LC/MS): 346 [M+Na]+, 268 [MH−tBu]+, 224 [MH−Boc]+; tR (HPLC conditions b): 5.31 min. The title compound was prepared in a similar manner to warm to RT stirred overnight After cooling to 0° C. the reaction was quenched with MeOH followed by addition of aqueous NaHCO3 solution Volatiles were removed under reduced pressure The organics were washed with aqueous NaHCO3 (3×), water and brine dried (Phase separator) concentrated in vacuo The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 1:9)

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of (2S,3R)-3-hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester [186132-96-7] (500 mg, 2.162 mmol; Chem-Impex International, Inc.) in MeOH (9.0 mL), cooled to 0° C., was added with stirring a solution of Cs2CO3 (704 mg, 2.162 mmol) in water (6.0 mL). The mixture was concentrated by rotary evaporation and the residue was suspended in DMF (17.0 mL). The suspension was cooled to 0° C., followed by addition of benzylbromide (0.514 mL, 4.32 mmol) and stirring overnight at RT. The reaction mixture was filtered, the filtrate was concentrated under reduced pressure and the residue was dissolved in EtOAc. The organics were washed with aqueous NaHCO3 (2×) and water (2×), dried (Phase separator) and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 2:3) to give the title compound as an oil. MS (LC/MS): 322 [M+H]+, 665 [2M+Na]+; tR (HPLC conditions b): 4.12 min. was added The mixture was concentrated by rotary evaporation The reaction mixture was filtered the filtrate was concentrated under reduced pressure the residue was dissolved in EtOAc The organics were washed with aqueous NaHCO3 (2×) and water (2×) dried (Phase separator) concentrated in vacuo The residue was purified by flash column chromatography on silica gel (EtOAc/c-hexane 2:3)