Benzyl Bromide → (1R,3S,5R)-2-Aza-bicyclo[3.1.0]hexane-2,3-dicarboxylic acid 3-benzyl ester 2-tert-butyl ester

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Reaction Conditions

Reaction Steps

To a solution of (1R,3S,5R)-2-aza-bicyclo[3.1.0]hexane-2,3-dicarboxylic acid 2-tert-butyl ester (2 g, 8.8 mmol) cooled at 0° C. was added a solution of Cs2CO3 (2.87 g, 8.8 mmol) in water (12.3 mL). After 30 min stirring, the resulting mixture was concentrated and the residue was suspended in DMF (41 mL). The suspension was cooled to 0° C. and benzylbromide (1.045 mL, 8.8 mmol) was added under nitrogen atmosphere. The reaction mixture was stirred at RT for 16 h. DMF was evaporated, the residue was poured in water and extracted with EtOAc (3×50 mL). The combined organic extracts were dried (Phase separator) and concentrated under reduced pressure. The residual oil was purified by flash column chromatography on silica gel (c-hexane/EtOAc 10:0 to 8:2) to give the title compound. TLC, Rf (c-hexane/EtOAc 8:2)=0.45; MS (UPLC-MS): 318 [M+H]+; tR (HPLC conditions d): 3.89 min.

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