A highly stereoselective and substrate-controlled synthesis of polycyclic β-lactams from d-glucose derived chiral template via intramolecular radical cyclization is described. The cyclization is highly substrate dependant, proceeding via 6-exo and 7-endo heptenyl type radical cyclization with the radical acceptor allyl group at N-1 and the radical progenitor on a sugar moiety, anchored to the β-lactam ring at C-4. The mode of radical cyclization in N-propargyl substrates is highly stereospecific and controlled by the stereochemistry of the β-lactam ring.
azetidin-2-ones - polycyclic β-lactams - radical cyclization - glucose - tributyltin hydride
