title: Convergent and stereodivergent synthesis of complex 1-aza-7-oxabicyclo[2.2.1]heptanes.
abstract: A convergent and stereodivergent pathway to highly substituted 1-aza-7-oxabicyclo[2.2.1]heptanes is described. It begins with a coupling reaction involving allylic alcohol, aldehyde, and LiHMDS to produce stereodefined primary homoallylic amines. Subsequent N-oxidation and condensation with formaldehyde or glyoxylate defines a convenient entry to densely functionalized homoallylic nitrones whose intramolecular annulation can be controlled to deliver one of two distinct heterocyclic skeletons, each with ≥20:1 stereoselection. Control of the stereochemistry in these reactions results from both control of the nitrone geometry and selective partitioning of the reaction pathway between direct [3 + 2] cycloaddition and tandem [3,3] rearrangement/[3 + 2] cycloaddition.
authors: Department of Chemistry, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA.
authors: Dexi
authors: D
authors: Yang
authors: Glenn C
authors: GC
authors: Micalizio
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