Uses
L-Valinol is used as a reagent in the synthesis of simple 1,3-thiazolidine-2-thione derivatives which can exhibit fungicidal activity. L-Valinol is also used as a reagent in the synthesis of small-molecule inhibitors of MDM2-p53 protein-protein interaction (MDM2 inhibitors) in clinical trials for the treatment of cancer.
Purification Methods
Purify S-valinol by vacuum distillation using a short Vigreux column (p 11). Alternatively it is purified by steam distillation. The steam distillate is acidified with HCl; the aqueous layer is collected and evaporated. The residue is dissolved in butan-1-ol, filtered and dry Et2O added to crystallise the hydrochloride salt (hygroscopic), m 113o. The free base can be obtained by suspending the salt in Et2O and adding small volumes of saturated aqueous K2CO3 until effervescence is complete and the mixture is distinctly alkaline. At this stage the aqueous layer should appear as a white sludge. The mixture is heated to boiling and refluxed for 30minutes (more Et2O is added if necessary). Purification of Biochemicals — Amino Acids and Peptides The Et2O layer is decanted off from the white sludge, the sludge is extracted twice with Et2O (by boiling for a few minutes), the combined organic layers are dried (KOH pellets), evaporated and the residue is distilled in a vacuum. [Nagao et al. J Org Chem 55 1148 1990, Beilstein 4 III 805.]
