Syntheses and Glycosidase Inhibitory Activities of 2‐(Aminomethyl)‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol Derivatives

New 2‐(aminomethyl)‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol derivatives were synthesized from (5 S )‐5‐[(trityloxy)methyl]pyrrolidin‐2‐one ( 6 ) ( Schemes 1 and 2 ) and their inhibitory activities toward 25 glycosidases assayed ( Table ). The influence of the configuration of the pyrrolidine ring on glycosidase inhibition was evaluated. (2 R ,3 R ,4 S ,5 R )‐2‐[(benzylamino)methyl]‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol ((+)‐ 21 ) was found to be a good and selective inhibitor of α ‐mannosidase from jack bean ( K i =1.2 μ M ) and from almond ( K i =1.0 μ M ). Selectivity was lost for the non‐benzylated derivative (2 R ,3 R ,4 S ,5 R )‐2‐(aminomethyl)‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol ((+)‐ 22 ) which inhibited α ‐galactosidases, β ‐galactosidases, β ‐glucosidases, and α ‐ N ‐acetylgalactosaminidase as well.