New Regiocontrolled Synthesis of Functionalized Pyrroles from 2‐Azetidinone‐Tethered Allenols

A new one-pot approach to synthesize densely substituted racemic and enantiopure pyrroles from β-lactams has been developed. The approach relies on the regiocontrolled cyclization of β-allenamine intermediates derived from the ring opening of 2-azetidinone-tethered allenols. In this approach four points of diversity are introduced, one of which is the position of the allene moiety on the β-lactam ring.