Domino synthesis of bridged bicyclic tetrahydro-1,2-oxazines: access to stereodefined 4-aminocyclohexanols.

The intramolecular variant of the homo-[3 + 2]-dipolar cycloaddition of nitrones (generated in situ from an aldehyde and a hydroxylamine) with donor-acceptor cyclopropanes allows for the efficient synthesis of bridged tetrahydro-1,2-oxazines. This domino sequence produces adducts amenable to reductive N-O bond cleavage producing cis-1,4-aminocyclohexanols in excellent yields.