Half a second in solution at room temperature is the lifetime of didurylcarbene (1). This species is generated thermally and photochemically from the corresponding diazo compound and reacts by dimerization and by intramolecular H abstraction. The ortho methyl groups are key to stabilizing the carbene, and the meta methyl groups exert an additional buttressing effect.
No takes yet. Share an insight, caveat, or question.
Tomioka et al. (1994) studied this question.