Patent ID: 8884005

Claim:
A method of preparing a β-lactam compound defined by the formula 9, where: R 1 is a C 1-6 alkyl, C 3-6 -alkene, C 1-6 -alkoxymethyl, benzyloxymethyl, a hydroxy-C 1-6 -alkyl, an O-protected hydroxy-C 1-6 -alkyl, a dihydroxy-C 1-6 -alkyl or an O, O′-protected dihydroxy-C 1-6 -alkyl wherein both hydroxyl groups may have the same or different protecting groups, and further wherein the protection of both hydroxyl groups is by a cyclic acetal or ketal group, R 2 is a C-alkyl, allyl, benzyl, substituted benzyl, silyl, C 1-6 -alkoxymethyl, benzyloxymethyl, C 1-6 -alkylsulphonyl, arylsulphonyl or acyl group; R 3 is a C 1-6 -alkyl, allyl, benzyl, substituted benzyl, silyl, C 1-6 -alkoxymethyl, benzyloxymethyl, C 1-6 -alkylsulphonyl, arylsulphonyl or acyl group; R 2 and R 3 taken together form a cyclic acetal or ketal group; R 4 is a hydrogen atom, methyl, C 1-6 -alkoxyl, C 1-6 -alkoxymethyl, allyl benzyloxymethyl, benzyloxyl, siloxyl or acyloxyl group; comprising reacting an acetylene compound 10 with a nitrone defined by the general formula 11, in the presence of a copper salt, a base and optionally a solvent.