monoterpenoid (±)-schefflone via ortho-quinone methide intermediate. The heating of 6-[(dibenzylamino)methyl]-3-isopropyl-2,4-dimethoxyphenol also results in ortho-quinone methide intermediate which is trapped by 3-(dimethylamino)-5,5-dimethylcyclohex-2-en-1-one or benzotriazole. (±)-schefflone - ortho-quinone methide - espintanol - trimerization - Diels-Alder reaction