2-Iminooxetanes (1), generated by lanthanide-catalyzed heterocycloaddition of aldehydes to ketene imines, are versatile synthons for beta-lactams (2) and for beta-keto amides (3). Conversion of 1 into 2 and 3 can be accomplished by either lanthanide-induced or oxidative (DMSO) ring opening, respectively.
2-Iminooxetane chemistry. 2. General synthesis from ketene imine-aldehyde cycloadditions