Formation of 1,2-dioxanes by the use of tris(2,4-pentanedionato)- manganese(iii) or manganese(iii) acetate

Abstract

The reactions of 1, 1-diphenylethene, 1, i-bis(4-chlorophenyl)ethene, 1, 1-bis(4-methoxyphenyl)ethene, 1, 1-bis(4- methylphenyl)ethene, 1,1-bis(4-fluorophenyl)ethene, styrene, 1-octene, cyclohexene, and cyclooctene with tris(2,4- pentanedionato)manganese(III) ({Mn(acac)s]) in acetic acid at room temperature give 4-acetyl-3-methyl-1,2-dioxan- 3-ol in 8 92% yields, together with 3-acetyl-4-hydroxy-3-hexene-2,5-dione. The similar reactions of 1,1- diphenylethene with 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, l-phenyl-l ,3- butanedione, acetoacetanilide, and 1 ,3-cyclohexanedione in the presence of manganese(III) acetate also give the corresponding cyclic peroxide in good to moderate yields. The mechanisms of manganese(III)-induced 1,2- dioxane ring formation and concomitant radical side reaction are discussed. © 1991 The Chemical Society of Japan.