Synthesis of mono- and dihydroxy-substituted 2-aminocyclooctanecarboxylic acid enantiomers
Abstract (1R,2S,6R)-2-Amino-6-hydroxycyclooctanecarboxylic acid (−)-10 was synthesized from (1R,2S)-2-aminocyclooct-5-enecarboxylic acid (+)-2 via an iodolactone intermediate, while (1R,2S,3R,4S)-2-amino-5,6-dihydroxycyclooctanecarboxylic acid (−)-12 was prepared by using the OsO4-catalyzed oxidation of Boc-protected amino ester (−)-5. The stereochemistry and relative configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy (based on 2D NOE cross-peaks and 3J(H,H) coupling constants) and X-ray crystallography.