An Improved Procedure for the Preparation of the Garner Aldehyde and Its Use for the Synthesis of<i>N</i>-Protected 1-Halo-2-(<i>R</i>)-amino-3-butenes

An improved procedure for the preparation of 1,1-dimethylethyl 2,2-dimethyl-4-(S)-formyloxazolidine-3-carboxylate (Garner aldehyde) is described which avoids the need for methyl iodide and benzene. Elaboration of this aldehyde into the novel chiral building blocks mentioned in the title is also described.