Cyclialkylation studies. 3. Acid-catalyzed cyclodehydration of some benzyltetralols, with and without rearrangement, to yield tetracyclic hydrocarbons
作者:Ramanujam S. Prasad、Royston M. Roberts
DOI:10.1021/jo00009a013
日期:1991.4
Acid-catalyzed cyclodehydration of some benzyltetralols has been used to prepare tetracyclic hydrocarbons as synthons for compounds of potential pharmacological value. Upon treatment with sulfuric acid at 25 or 40-degrees-C, 4-benzyl-2-tetralol (15) gave a 70:30 mixture of 2,3:6,7-dibenzobicyclo[3.2.2]nona-2,6-diene (7) and 2,3:6,7-dibenzobicyclo[3.3.1]nona-2,6-diene (8). Reaction of 15 with p-toluenesulfonic acid in refluxing cyclohexane solution gave the same two products (7 and 8) as well as a small amount of 1-benzyl-1,2-dihydronaphthalene (16). Treatment of either 15 or 16 with AlCl3 gave only 8. Treatment of 1-benzyl-2-tetralol (17) with AlCl3 also gave 8. The mechanism of formation of 7 and 8 from 15 and 16 is discussed.