Synthesis of 2,3,5-trisubstituted furans by the acid-catalyzed decomposition of 1,2-dioxan-3-ols

Thirteen new 2,3,5-trisubstituted furans were prepared by the acid-catalyzed decomposition of 6,6-di-substituted 1,2-dioxan-3-ols in 57-93% yields. The reaction could be accounted for as the consequence of an oxygen-oxygen bond cleavage by acid and the migration of a phenyl group at the C-6 position followed by cyclization and elimination of a phenol. The migratory aptitude was in the order of 4-MeOC₆H₄- > 4-MeC₆H₄- > Ph- = 4-FC₆H₄- > 4-ClC₆H₄- = 4-BrC₆H₄- that was found from the competitive phenyl migration in the reaction of 1,2-dioxan-3-ols bearing two different substituents at the C-6 position.