isofagomine, 3‐deoxyisofagomine, and numerous other N‐alkoxy analogues. The barrier to inversion in these polyhydroxylated N‐alkoxypiperidine derivatives was found by variable‐temperature NMR methods to be approximately 15 kcal mol−1. With the exception of N‐hydroxyisofagomine itself, none of the compounds prepared showed significant inhibitory activity against sweet almond β‐glucosidase.