Valinol Explained

Valinol is an organic compound named after, and commonly produced from, the amino acid valine. The compound is chiral and is produced almost exclusively as the S‑isomer (also designated as the L‑isomer), due to the abundant supply of S-valine. It is part of a broader class of amino alcohols.

Synthesis

Valinol can be generated by converting the carboxylic group of valine to an alcohol with a strong reducing agent such as lithium aluminium hydride,^[1] or with NaBH₄ and I₂ (forming the borane–tetrahydrofuran complex).^[2] In both cases the valinol produced can be subsequently purified by short path distillation.

Reactions

Valinol is mainly used to prepare chiral oxazolines, a process which can be achieved via a variety of methods. These oxazolines are principally used as ligands in asymmetric catalysis.^[3]

See also

• (S)-iPr-PHOX - an oxazoline ligand made using valinol

References

1. Dickman. D.A.. Meyers, A.I. . Smith, G.A. . Gawley, R.E. . Reduction of α-Amino Acids. Organic Syntheses. 1990. 7. 530. 11 October 2012. 10.15227/orgsyn.063.0136.
2. McKennon. Marc J.. Meyers, A. I. . Drauz, Karlheinz . Schwarm, Michael . A convenient reduction of amino acids and their derivatives. The Journal of Organic Chemistry. 1993. 58. 13. 3568–3571. 10.1021/jo00065a020.
3. McManus. Helen A.. Guiry, Patrick J. . Recent Developments in the Application of Oxazoline-Containing Ligands in Asymmetric Catalysis. Chemical Reviews. 104. 9. 4151–4202. 10.1021/cr040642v. 15352789. Sep 2004.