A new diastereoselective synthetic approach towards 1,2,3-trisubstituted
pyrrolidines and 2,3-disubstituted tetrahydrofurans is described.
The synthesis of the pyrrolidines involves reductive cyclization
of γ-chloroketimines, which were generated in situ from
the reaction of 3-substituted 5-chloro-2-pentanones and a primary
amine. Various reduction conditions were explored to induce a diastereoselective
reductive cyclization. 2,3-Disubstituted tetrahydrofurans were obtained
by the direct reduction of 3-substituted 5-chloro-2-pentanones with
sodium borohydride.
pyrrolidines - tetrahydrofurans - cyclization - haloimines - haloketones
