Selectivity in Radical Halogenation with Fluorine and Bromine

Give products and the ratio in which they are expected to form for the monochlorination of 3-methylpentane at 25°C. (Caution Be sure to take into account the number of hydrogens in each distinct group in the starting alkane.) 

In Summary The relative reactivity of primary, secondary, and tertiary hydrogens follows the trend expected on the basis of their relative C-H bond strengths. Relative reactivity ratios can be calculated by factoring out statistical considerations. These ratios are temperature dependent, with greater selectivity at lower temperatures. 

SELECTIVITY IN RADICAL HALOGENATION WITH FLUORINE AND BROMINE 

To answer this question, consider the reactions of fluorine and bromine with 2-methyl-propane. Single fluorination at 25°C furnishes two possible products, in a ratio very close to that expected statistically. 

Energies of late transition states are dissimilar and relatively large 

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Selectivity in Radical Halogenation with Fluorine and Bromine CHAPTER 3... 

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