D. Neville et Ws. Murphy, NOVEL LEWIS-ACID PROMOTED SPIROANNULATION VERSUS [2-CYCLOADDITION OF DIHYDROFURAN AND DIHYDROPYRAN TO QUINONES(2]), Tetrahedron letters, 37(29), 1996, pp. 5221-5224
Dihydrofuran was found to undergo dimethylaluminium chloride promoted
[2+2]-cycloaddition with benzo- and naphthoquinone. The first example
of a novel spiroannulation was observed with methoxybenzoquinone. With
dihydropyran, spiroannulation only, occurred in all cases investigate
d. Copyright (C) 1996 Elsevier Science Ltd