Kinetic and thermodynamic azides from α-triflates of γ-lactones: Intermediates for the incorporation of polyhydroxylated D- and L-α-aminoacids into combinatorial libraries
Krülle TM., Davis B., Ardron H., Long DD., Hindle NA., Smith C., Brown D., Lane AL., Watkin DJ., Marquess DG., Fleet GWJ.
Displacement of α-triflates of 2,3,4-all cis-substituted γ-lactones by sodium azide in DMF gives kinetically an azide with inversion of configuration at the C-2 of the lactone; under the reaction conditions, the initially formed azide epimerises to the apparently more crowded and thermodynamically stable all cis-azide, giving intermediates which should readily allow the incorporation of polyhydroxylated amino acids into combinatorial libraries.