Abstract
A straightforward synthesis of L-azetidine-2-carboxylic acid is described, leading to both orthogonally protected versions or totally deprotected L-Aze. The starting material is a commercially available aspartic acid derivative, whose chirality is conserved. The (2-trimethylsilyl)ethaneslfonyl protecting group (SES) acts as a leaving group on the hydroxy function and serves as an activator for the amine function, which is the key-step of the reaction.