Methyl 3,4-O-isopropylidene-L-threonate 3 was identified as a commercially available chiral feedstock, and was itself synthesized in-house in excellent yield using inexpensive reagents in 3-steps from vitamin C (Scheme 2A). Subsequent substitution of the secondary alcohol in 3 via SN2 attack with sodium azide, followed by Staudinger reduction, Fmoc-protection and methyl ester hydrolysis, allowed N-Fmoc-protected SPPS-compatible hThr L-amino acid 6 to be accessed in a further 4-steps from 3. The additional chiral center of the protected 1,2-diol motif allowed 6 to be verified as a pure L-amino acid by NMR.