Synthesis of (R)-tert-Leucinol by Classical Resolution of the Racemic Mixture

Optically active tert‐leucinol is an important building block in asymmetric synthesis. However, the (R) enantiomer particularly has so far remained difficult to obtain, mainly because of the laborious synthesis of the precursor amino acid, (R)‐tert‐leucine. Here we present a new, classical resolution of racemic tert‐leucinol, which allows straightforward preparation of each, but especially the (R) enantiomer, in good yields and high optical purities. The feasibility of the synthesis of useful derivatives is demonstrated by transformation into the corresponding (R)‐4‐tert‐butyl‐2‐oxazolidinone. Good yields and high optical purities are obtained in a new classical resolution of racemic mixtures of tert‐leucinol (1), especially of the so far not easily available (R) enantiomer. The usefulness of this procedure in the preparation of derivatives for asymmetric synthesis was demonstrated by the transformation of (R)‐tert‐leucinol thus obtained into the optically pure oxazolidinone (R)‐2.