Stereoselective Total Synthesis of Aminoiminohexitols via Carbamate Annulation

New methodology for the preparation of a variety of aminoiminohextitols
is described. Key in the synthesis is the application of a diastereoselective
Strecker reaction and the extension of our carbamate annulation methodology
to protected and functionalized alkenylamines. Insight into the effects
that the substitution patterns of the alkenylamines have on the diastereoselectivity
of the iodocyclization and carbamate annulation is discussed. An evaluation
of the glycosidase inhibitory activity of the aminoiminohexitols and
derivatives is also presented, with the previously undisclosed d-talo isomer showing good selective inhibition
of β-d-glucosidase.