Synthesis of some polyhydroxylated pyrrolidine derivatives.

Polyhydroxylated pyrrolidine, piperidine, and indolizidine alkaloids are of great interest because of their specific glycosidase inhibitory activity." Moreover, it has recently been found in our laboratories that swainsonine (1), a representative of the polyhydroxylated indolizidine alkaloids, has an immunostimulating activity, possibly as a result of its glycosidase inhibitory activity.21 This has prompted us to explore related pyrrolidine and piperidine alkaloids. In the preceding paper,31 we reported the syntheses of two piperidine alkaloids, deoxynojirimycin (2) and deoxymannojirimycin (3). Herein we report the syntheses and biological activity of some pyrrolidine derivatives 7, 11, 15, and 18.