1,4-Bis(tert-butoxycarbonyl)-2-formylmethylpiperazine → 2(S)-(2(R)-hydroxypropyl)piperazine-1,4-dicarboxylic acid di-tert-butyl ester

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Reaction Steps

Add methylmagnesium bromide (3.61 mL, 10.8 mmol, 3M solution in diethyl ether) to a solution of 2-(2-oxoethyl)piperazine-1,4-dicarboxylic acid di-tert-butyl ester (3.036 g, 9.84 mmol) in tetrahydrofuran (30 mL) at 0° C. Warm the mixture to room temperature and stir for 5 hours. Dilute the mixture with saturated ammonium chloride and extract three times with ethyl acetate. Combine the organic layers, dry over sodium sulfate and concentrate under reduced pressure to give 2(S)-(2(S)-hydroxypropyl)piperazine-1,4-dicarboxylic acid di-tert-butyl ester and 2(S)-(2(R)-hydroxypropyl)piperazine-1,4-dicarboxylic acid di-tert-butyl ester (3.37 g, 99%) as a yellow oily solid: mass spectrum (APCI): m/z=245.2 (M+1-BOC).

Provenance & Evidence