摘要
A large body of facts has shown that, for the ionic addition reactions of an unsymmetrical reagent onto an unsymmetrical ethylenic bond, the two possible position isomers of the products are formed almost always together, and that under the same conditions the relative amounts of these two isomeric products depend upon both the reactivity of the addition reagents and the structure of the olefins. The prevailing orientation rule based on the electronic theory and the classical Markownikoff rule formulated on the basis of the number of hydrogen atoms attached to the ethylenic carbons, have been found to be very successful in giving the correct orientation of the main addition product. They leave, however, the quantitative aspects of the addition reactions (such as the definite
