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Racemic mixtures converted to single pure enantiomers
Dynamic resolution of crystalline imines, a new method developed at Co. can convert an entire racemic mixture of an unfunctionalized ketone or aldehyde into one pure enantiomer. "We are confident that this new methodology will find widespread industrial utility. team members screened a number of single-enantiomer primary amines to find one that performed as they hoped. The amine shown in the scheme above reacts with (R,S)-2-methylcyclohexanone to produce a mixture of four isomeric imines that equilibrate in solution. But only a single isomer crystallizes out, dynamically shifting the equilibrium. Careful hydrolysis of the crystalline imine yields close to 100% of the R-enantiomer of the starting ketone. The chemists so far have obtained similar results with an aldehyde and three additional ketones.
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