Text this: Looking glass inhibitors: scalable syntheses of DNJ, DMDP, and (3R)-3-hydroxy-L-bulgecinine from D-glucuronolactone and of L-DNJ, L-DMDP, and (3S)-3-hydroxy-D-bulgecinine from L-glucuronolactone. DMDP inhibits beta-glucosidases and beta-galactosidases whereas L-DMDP is a potent and specific inhibitor of alpha-glucosidases