Abstract: The preparation and acetolysis of 2-methyl-3, 4-pentadien-l-yl tosylate (IIIb) and model compound 2-methyl-1-pentyl tosylate are reported. Compound IIIb undergoes acetolysis with accompanying return-rearrangement to the same rearranged tosylate afforded by 4, 5-hexadien-2-yl tosylate (X). Both I11 band X yield essentially identical product mixtures, suggesting that both solvolyze through the same ion (manifold). The ...