Origins of Selectivities in the Stork Diels–Alder Cycloaddition for the Synthesis of (±)-4-Methylenegermine

The remarkably high  stereoselectivity of  a Diels–Alder cycloaddition  designed by  Stork for the synthesis of germine has been examined with theory. We conceived a collaboration with Gilbert Stork, the great synthetic chemist and collaborator. We wished to complement Stork's insights with computations to explain the extraordinary selectivity he designed to introduce four new stereocenters in one step. Stork passed away on October 21, 2017, at age 95, sadly before we finished this work.