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(R)-(+)- and (S)-(–)-Stericol® New, Effective Chiral Auxiliaries

By: Mark Redlich, Chemfiles Volume 9 Article 3

The introduction of chirality to organic molecules through the use of auxiliaries is a basic strategy in organic chemistry. Chiral benzylic alcohols are of particular interest because they often afford useful levels of stereoselection and are generally easy to cleave.

Preparation of Dichlorocyclobutanones


Preparation of Dichlorocyclobutanones

Asymmetric Oxidation of Benzenesulfenates


Asymmetric Oxidation of Benzenesulfenates

Preparation of β,γ-Unsaturated Silyl Sulfinates


Preparation of β,γ-Unsaturated Silyl Sulfinates

The enantiomers of 1-(2,4,6-triisopropyl)phenylethanol ((R)- and (S)-Stericol®) are especially beneficial as chiral auxiliaries, providing high diasteromeric ratios in [2+2] cycloadditions,1 oxidations,2and carbon-carbon bond forming reactions.3

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References

  1. (a) de Azevedo, M. B. M.; Greene, A. E. J. Org. Chem. 1995, 60, 4940. (b) Kanazawa, A. et al. J. Chem. Soc. Perkin Trans. 1997,1911. (c) Nebois, P.; Greene, A. E. J. Org. Chem. 1996, 61, 5210. (d) Ceccon, J. et al. Synlett 2005, 1413. (e) Roche, C. et al. Org. Lett. 2003, 5, 1741. (f) Muniz, M. N. et al. Synlett 2005, 1328. (g) Roche, C. et al. J. Org. Chem. 2005, 70, 8352. (h) Ceccon, J. et al. Org. Lett. 2006, 8, 4739.
  2. Hamel, M.; Grach, G.; Abrunhosa, I.; Gulea, M.; Masson, S.; Vazeux, M.; Drabowicz, J.; Mikolajczyk, M. Tetrahedron: Asymmetry 2005, 16, 3406.
  3. (a) Narkevitch, V. et al. Angew. Chem., Int. Ed. 2000, 39, 1806. (b) Bouchez, L. C. et al. Tetrahedron 2005, 61, 11473. (c) Narkevitch, V. et al. J. Org. Chem. 2001, 66, 5080.

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