Highly Functionalized Cyclopentanes from Meso Bicyclic Hydrazines. A Rapid Access to Mannosidase Inhibitors

A simple diastereoselective access to amino- and hydrazinocyclopentitols is described. The key step involves a cationic rearrangement of a meso bicyclic hydrazine, followed by two successive stereoselective hydroxylations. Both racemic compounds are micromolar α-mannosidase (Jack bean) inhibitors.