J. Lars, G. Nilsson, H. Selander
1970
Citations
0
Influential Citations
11
Citations
Journal
Tetrahedron
Abstract
2,3Dihydro-5-benzofuranols related to β- and γ-tocopherol and to tocol have been synthesized and their oxidation with alkaline ferricyanide has been studied. Oxidation of 2,3-dihydro-2,2-dimethyl-5-benzofuranol gave a spiroketal trimer 10 by CC and CO coupling via the 6-position of the molecule. This indicates a directing effect on the oxidative coupling by the annelated 5-membered heterocyclic ring which is in accord with the predictions based on the Mills-Nixon effect. Similar oxidation of 2,3-dihydro-2,2,4,7-tetramethyl-5-benzofuranol and of 2,3-dihydro-2,2,6,7-tetramethyl-5-benzofuranol (analogues of β- and γ-tocopherol, respectively) gave the hydroxyquinones 11 and 12 by reactions involving opening of the heterocyclic ring.