| abstract |
Disclosed is a process for the synthesis of N-protected 4-keto-prolines (1), starting with the corresponding protected 4-hydroxyproline, in the presence of the oxidising system P 2 O 5 /dimethylsulphoxide (DMSO). Said process can also be applied in the presence of a chiral centre in the position bearing carboxylic acid (the 3 position) without significant epimerisation of said centre. Said process is particularly advantageous from the environmental standpoint and in terms of yields, productivity and the purity of the product obtained, since it does not use chromium-based oxidants, metals such as ruthenium, or oxidising systems which are precursors of genotoxic impurities. |