(+/-)-Isofagomine (1) and all its stereoisomers were prepared in a short sy
nthesis from arecoline. The double bond of arecoline was isomerised to be n
o longer conjugated to the carboxy, and the ester reduced to (hydroxymethyl
)tetrahydropyridine 5 which after dihydroxylation of the alkene, separation
and N-demethylation gave 1 and its isomers.