Synthesis of Novel and Uniquely Shaped 3-Azabicyclo[4.2.0]octan-4-one Derivatives by Sequential Ugi/[2+2] Ene−Enone Photocycloadditions

We report a new methodology for the construction of novel and uniquely shaped 3-azabicyclo[4.2.0]octan-4-one derivatives by combining the
Ugi multicomponent reaction with [2+2] enone−olefin photochemical transformations. The overall sequence is capable of creating up to five
stereocenters; however, in most cases, only two diastereomers are observed.