Di‐<i>tert</i>‐Butyl Acetylenedicarboxylate and Its Cyclotrimerization

Abstract

Di‐ tert —butylacetylenedicarboxylate (1) —surprisingly not synthesized before—is remarkable from a chemical standpoint. Its cyclotrimerization shows that the tert ‐butyl groups do not exert strong steric hindrance. Ready cleavage (without base) of the esters obtained from (1) is of advantage. equation image