The Reaction of Optically Active Silver β-Phenylisobutyrate with Halogen

The Hunsdiecker reaction of optically active silver β-phenylisobutyrate with bromine was carried out, and racemic β-phenylisopropyl bromide and optically atcive 3-methyl-7-bromo-hydrocoumarin were obtained as the major products. Meanwhile, the Simonini reaction was also performed with the same optically active acid and iodine; 1-phenyl-2-propyl β-phenylisobutyrate was obtained as the product here. Upon the hydrolysis of the ester, the resulting alcohol, β-phenylisopropyl alcohol, was found to be racemic. From these observations, the mechanisms involving the formation of the incipient free radical during the reactions were suggested for both the reactions.