Disclosed are new compounds of formulae: Wherein: R1 and R2 can be independently H; a C1 to C6 alkyl including methyl, ethyl, propyl, butyl; aryl including phenyl, para-methoxyphenyl; or R1,R2 together with the carbon C-6 can be a cyclopentylidene or cyclohexylidene; each of these groups being substituted or not; and R3 can be a C1 to C6 alkyl including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl; or aryl including phenyl, methylphenyl, ethylphenyl, each of these groups being substituted or not. The invention also relates to their method of manufacture and their use for the synthesis of Ara-N3, Kdo-N3 and 4eKdo-N3.