Ar1-5 and Ar2-6 Aryl Participation in Ionic and Free Radical Processes

摘要

Participation of aryl groups in the solvolysis of 4-aryl-1-butyl halides and arylsulfonates, or in the reactions of 4-aryl-1-butyl free radicals, is illustrated and discussed. With properly methoxylated or hydroxylated 4-aryl-1-tmtyl derivatives, formolysis may involve either Ar1-5 or Ar2-6 aryl par¬ticipation. Such participation leads to formation of tetralin. Because Ar1-5 participation leads to a spiro earbonium ion, in which either Cα or Cδ of the original butyl side chain may shift, the final tetralin may be different from the one which would be formed by the more direct Ar2-6 route. A case in point is the formolysis of 4-p-anisyl-4-methyl-l-pentyl bromo-benzenesulfonate, the derived tetralin being essentially entirely the rear¬ranged one.