Novel Synthesis of 4-Carboxymethyl 5-Alkyl/Aryl Oxazolidin-2-ones by Rearrangement of 2-Carboxymethyl 3-Alkyl/Aryl N-tert-Butoxycarbonyl Aziridines
journal contributionposted on 03.12.1999, 00:00 by Claudia Tomasini, Andrea Vecchione
A two-step approach for the diastereoselective synthesis of 4-carboxymethyl 5-alkyl/aryl oxazolidin-2-ones is described, which proceeds via the intermediate formation of 2-carboxymethyl 3-alkyl/aryl N-tert-butoxycarbonyl (N-Boc) aziridines. By reaction of N-Boc β-amino methyl esters with LiHMDS and iodine, trans 2,3-disubstituted N-Boc aziridines are obtained with high stereoselectivities and yields. The final rearrangement to oxazolidin-2-ones is achieved by treatment with a catalytic amount of a Lewis acid and proceeds with high yield and complete regio- and stereoselectivity.