Nucleophilic Additions of 2-Furyllithium to Carbonyl Derivatives of L-Serine. Formal Synthesis of (2R,3R)-β-Hydroxy Aspartic Acid

The nucleophilic addition of 2-furyllithium to esters derived from L-serine is described. The obtained furyl ketone 5 is stereoselectively reduced (ds≥95%) with sodium borohydride to afford the corresponding syn aminoalcohol 12 in enantiomerically pure form. Compound 12 was further converted into valuable α-hydroxy-β-amino acids by means of the furan-to-acid equivalence.