Preliminary Studies on the Transformation of Nitrosugars into Branched Chain Iminosugars: Synthesis of 1,4-Dideoxy-4-<i>C</i>-hydroxymethyl- 1,4-imino-pentanols

A novel promising strategy for the transformation of nitrosugars into branched pyrrolidines, based on double Henry reaction with formaldehyde followed by reductive ring closure, allowed the first enantiospecific synthesis of a 4-C-hydroxymethyl branched derivative of the well-known glycosidase inhibitor 1,4-dideoxy-1,4-imino-pentanol. This strategy also afforded a new route to some other interesting derivatives, such as N-hydroxy, N-propyloxy, and imino derivatives, a new kind of compounds with promising biological properties.