Deoxygenation of Arene 1,4-Endoxides with Low-Valent Metals

Article abstract of DOI:10.1021/jo00320a005

Low-valent forms of iron, tungsten, and titanium, produced by treatment of the metal chlorides with butyllithium at -78 deg C, are useful deoxygenation catalysts for the conversion of 1,4-endoxides to the corresponding arenes in a single step.In some instances, particulary with highly substituted endoxides, other reactions may interefere.For example, with methyl substituents at C2 and C3 and with reduced iron, reduction of the C2-C3 double bond and a 1,3 hydrogen shift occur.Also, hindered aromatic methoxyls may be replaced by hydrogen.Use of this deoxygenationmethod to prepare 1,4,5,8,9,10-hexamethylanthracene, a compound with multiple peri interactions, is described.