Acetic acid--water (1/1) → (S)-di-tert-butyl-5-formylpyrrolidine-1,2-dicarboxylate

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Reaction Conditions

Reaction Steps

90 g Raney-Ni/H2O (50 w % in water, Acros) was added to a solution of 17.905 g (60.42 mmol) of the cyanide 110 in 640 ml Py/AcOH/H2O (2:1:1) and stirred under hydrogen for 72 h at 80° C. 300 ml water was added to the suspension, and the suspension was extracted 3× with 800 ml MTBE each. The combined organic phases were washed twice with water, dried over magnesium sulfate, and the solvent was removed at reduced pressure. The residue was filtered with 1000 ml EtOAc/CyHex (1:1) over silica gel, and, following the removal of the solvent, the raw product was purified by chromatography on silica gel with EtOAc/CyHex 1:4 as eluent. 9.234 g (30.85 mmol, 51%) of the aldehyde 111 was obtained as yellow oil (d.r.: 1.7:1 cis:trans).

Provenance & Evidence