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What is the major product of monochlorination of 2-methylpropane and for 2-methylbutane?

My attempt: as in 3 degree position, monochlorination is favoured (due to free radical formation), so according to me, it should be 2-chloro-2-methylpropane and same as in other 2-chloro-2-methylbutane.

But, it is stated to be incorrect. The correct answer is 1-chloro-2-methylbutane. Why's that the correct answer instead?

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    $\begingroup$ 1-chloro-2-methylbutane makes no sense to form as the major product. I highly suspect you are right, and the key might be wrong. $\endgroup$ – Pritt says Reinstate Monica Mar 31 '18 at 7:05
  • $\begingroup$ For each example consider the relative reactivity of each type of CH bond and the number of each one. ursula.chem.yale.edu/~chem220/chem220js/StudyAids.html#Radical $\endgroup$ – user55119 Mar 31 '18 at 15:05
  • $\begingroup$ @PrittBalagopal on the contrary, Cl isn't selective enough (contrary to bromine) $\endgroup$ – Mithoron Mar 31 '18 at 16:38
  • $\begingroup$ @Mithoron I believe that would simply reduce the % of 2-chloro-2-methylbutane in the product mixture as compared to other products, but I don’t really think it could actually flip the scenario (make 1-chloro more preferable). $\endgroup$ – Pritt says Reinstate Monica Mar 31 '18 at 16:42
  • $\begingroup$ And here I wonder why no one in 9 hours marked it as dupe of first question on the "related" list... $\endgroup$ – Mithoron Mar 31 '18 at 16:57