cis-Stereoselective SmI2-promoted reductive coupling of keto-nitrones: first synthesis of 1-epitrehazolamine

Abstract

An expeditious synthesis of 1-epitrehazolamine is presented from readily available 2,3,4,6-tetra-O-benzyl-D-glucose. The key step involves a samarium diiodide-promoted reductive cyclization of a masked keto-nitrone to form a five-membered ring aminocyclitol. The excellent cis selectivity observed in this nitrone–ketone reductive coupling contrasts surprisingly with the trans selectivity of ketone–oxime reductive couplings.