Hydrochloric Acid → (S)-Tert-butyl 1-cyclohexyl-3-oxopropan-2-ylcarbamate

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Reaction Steps

(S)-α-[[(1,1-Dimethylethoxy)carbonyl]amino]-N-methoxy-N-methylcyclohexanepropanamide (55.3 g., 175.9 mmole, 1 eq.) was dissolved in diethyl ether (1760 ml., 0.1M) and cooled in an ice bath. A solution of lithium aluminum hydride in tetrahydrofuran (193 ml., 193 mmole, 1.1 eq., 1M in tetrahydrofuran) was added dropwise over 90 minutes. After 75 minutes, a 1N HCl solution (1 1.) was added cautiously and slowly. The cooling bath was removed and the mixture was stirred for 2 hours. The layers were separated and the aqueous layer was reextracted with ether (2×400 ml.). The combined ether layers were dried (MgSO4) and freed of solvent in vacuo leaving a viscous oil (46.47 g. This was chromatographed on silica gel (500 g., Merck) which was packed in hexane. The aldehyde was eluted with ether:hexane 1:1) to give (S)-α-[[(1,1-dimethylethoxy)carbonyl]amino]cyclohexanepropanal.

Provenance & Evidence