Biologically active branched-chain aminocyclopentane tetraols from D-galactose

From 1,2;3,4-di-O-isopropylidene-d-galactopyranose, a series of highly functionalized branched-chain cyclopentanes was easily available. The initial partially protected cyclopentane tetraol is a versatile central intermediate and was exploited as subject to various highly regio- and stereoselective structural alterations with a view to prepare selective β-d-galactosidase inhibitors. In line with our findings on recently reported constitutional isomers featuring amino substituents, basic derivatives are medium activity inhibitors of β-d-galactosidases with side activities for β-glucosidases.