Synthesis and Transformations of Novel L‐Phenylalanine Derived Pyrazolidin‐3‐ones

Abstract

A simple and straightforward four-step synthesis of novel diastereomeric L-phenylalanine-derived pyrazolidin-3-ones is described. The absolute configuration of the novel C(5) stereogenic centre has been unambiguously determined by single crystal X-ray analysis and via chemical interconversions. A series of novel thiourea derived pyrazolidinones have been prepared and tested as potential organocatalysts. N(1) un-substituted pyrazolidinones can be used for the construction of a novel type of bicyclic heterocycles and other selective derivatizations.