The first synthesis of the single isomers (3R, 4R, 5R);(3S, 4S, 5S);(3R, 4R, 5S) and (3S, 4S, 5R) of 5-hydroxymethylpiperidine-3, 4-diol from Arecolin is reported, including the synthesis of a series of N-substituted derivatives of the (3R, 4R, 5R)-isomer (Isofagomine). The inhibitory effect of these isomers as well as of a series of N-substituted derivatives of the (3R, 4R, 5R)-isomer and selected hydroxypiperidine analogues on liver glycogen ...