Synthesis of all stereoisomers of 3-hydroxypipecolic acid and 3-hydroxy-4,5-dehydropipecolic acid and their evaluation as glycosidase inhibitors

A highly practicable synthesis of both enantiomers of 3-hydroxypipecolic acid derivatives 1, 2, 3, 4 is described. Screening of these molecules for glycosidase inhibition has been examined. Compound 3 was shown to be a potent inhibitor of β-N-acetylglucosaminidase as well as Escherichia coli β-glucuronidase.