Variable Strategy toward Carbasugars and Relatives As Illustrated by Diastereoselective Synthesis of 1-Deoxy-1-amino-pseudo-β-d-gulopyranose (Alias 1,2,4-Tri-<i>epi</i>-validamine)

A quick arrival at chiral nonracemic cyclohexanoids is provided, which incorporates useful variability for large product diversity. Central to the construction is the exploitation of the dual nucleophilic character of an easily accessible triad of silyloxy diene synthons derived from the popular five-membered heterocycles furan, pyrrole, and thiophene. To assess the reliability of the procedure, the total synthesis of 1-deoxy-1-amino-pseudo-β-d-gulopyranose (<b>10</b>) (alias 1,2,4-tri-<i>epi</i>-validamine) is executed, in 12 steps and with a 17% overall yield, by starting with <i>N</i>-<i>tert</i>-butoxycarbonyl-2-[(<i>tert</i>-butyldimethylsilyl)oxy]pyrrole (<b>1</b>) and 2,3-<i>O</i>-isopropylidene-d-glyceraldehyde (<b>2</b>).