Synthesis of (S)-N-tert-butoxycarbonyl-N,O-isopropylidene-α-methylserinal: A potential building block for the asymmetric synthesis of non-natural amino acids

Abstract The title compound ( S )- α -methylserinal acetonide has been efficiently prepared from ( S )- α -methylserine, which is readily available in enantiomerically pure form by Curtius rearrangement of α,α-dialkyl 2-cyanoesters obtained by diastereoselective alkylation of (1 S ,2 R ,4 R )-10-dicyclohexylsulfamoylisobornyl 2-cyanopropanoate using methoxymethyl iodide or paraformaldehyde as electrophiles by an extension of our recently developed methodology for the synthesis of α,α-dialkylamino acids.