A Novel Dimer of α-Tocopherol

Abstract

Decomposition of the complex 4, formed between the α-tocopherol ortho-quinone methide (2) and NMMO, by fast heating from −78∘C to 70∘C in inert solvents produces a novel α-tocopherol dimer with 6H,12H-dibenzo[b,f][1,5]dioxocine structure (5) which—in contrast to the well-known spiro-dimer of α-tocopherol (3)—is symmetrical. This is the first example of a direct reaction of the highly transient zwitterionic, aromatic precursor 2a in the formation of the ortho-quinone methide 2.