Asymmetric synthesis of (2R,3S)-3-hydroxypipecolic acid δ-lactam derivatives

A practical synthetic scheme that incorporates an amide functionality into the rigid framework of (2S,3R)-3-hydroxypipecolic acid to produce novel hydroxylated δ-lactam derivatives is reported. The reaction sequence includes the transformation of chiral furanylazide to a 2S-hydroxymethyldihydro pyridone, which was reduced diasteroselectively, protected and oxidized to two corresponding δ-lactam derivatives. Asymmetric dihydroxylation and oxidation of the latter compounds afforded two chiral (2R,3S)-3-hydroxypipecolic acid δ-lactam derivatives.