Markownikoff Rule; Peroxide effect.
Haloacids, when added across an unsymmetrical ethylenic
compound, the halogen usually bonds
to the least substituted ethylene carbon. However, for HBr, the
order of addition is often reversed
if peroxide is present.
W. Markownikoff, Ann. 153, 256 (1870)
M. S. Kharasch and and F. R. Mayo, J. Am. Chem. Soc. 55, 2468
(1933)
F. R. Mayo and C. Walling, Chem. Revs. 27, 351 (1940)
J. I. G. Cadogan and D. H. Hey, Quart. Rev. (London) 8, 308
(1954)
F. W. Stacey and J. H. Harris, Jr. in Organic Reactions 13, 155
(1963)