Synthesis of GABOB and GABOB-Based Chiral Units Possessing Distinct Protecting Groups

In addition to the varied biological activity of GABOB (4-amino-3-hydroxybutanoic acid), the structure of its protected derivatives makes them interesting chiral intermediates for the synthesis of more complex compounds. A stereoselective route to GABOB derivatives with three different protecting groups is presented, using anhydride desymmetrization as a chirality-inducing step. Selective removal of the protecting groups gave compounds with a free carboxylic acid or hydroxy group. Removal of all of the protecting groups allowed GABOB to be isolated in good yield and with excellent ee.