Synthetic uses of serine, threonine and cysteine

Abstract L-serine, L-threonine and L-cysteine are useful optically active precursors for the asymmetric synthesis of a wide variety of molecules such as amino acids1-3 or other nitrogen-containing targets. Commercially available, they offer a great challenge to the synthetic chemist in terms of stereochemical control and efficiency. In particular, the preparation of various serine-, threonine- and cysteine-derived aldehydes for synthetic purposes requires four conditions: Carboxy group modifications are generally undertaken after suitable protection of the OH (or SH) and NH2 functionalities. The preparation of N protected a-amino aldehydes has received much attention in recent years.13 They are usually purified by vacuum distillation,