Why would the concentrated hydrobromic acid be an

This preview shows page 18 - 25 out of 54 pages.

Why would the concentrated hydrobromic acid be an inappropriate catalyst for the dehydration of alcohols? a) HBr is too weakly acidic to protonate the alcohol. b) The conjugate base, Br - , is a good nucleophile and it would attack the carbocation to form an alkyl bromide. c) HBr is strongly acidic, so the water molecule would not be a good leaving group after protonation of the alcohol. d) HBr would be more likely to promote rearrangement of the carbocation intermediate.
PRACTICE: Which carbocation would not be likely to undergo rearrangement? 18
USF - ORGANIC CHEMISTRY I - PROF. FIELDS PRACTICE TEST: ACS ORGO 1 PRACTICE TEST PRACTICE: Which alcohol is dehydrated fastest in concentrated H 2 SO 4 PRACTICE: What reagent could accomplish this reaction? ? 19
USF - ORGANIC CHEMISTRY I - PROF. FIELDS PRACTICE TEST: ACS ORGO 1 PRACTICE TEST PRACTICE: Consider this prototypical nuclephilic substitution shown in the box. The effect of doubling the volume of solvent would be to multiply the reaction rate by a factor of
PRACTICE: If this alcohol is dehydrated, which alkene is likely to be formed in the largest quantity? 20
USF - ORGANIC CHEMISTRY I - PROF. FIELDS PRACTICE TEST: ACS ORGO 1 PRACTICE TEST PRACTICE: What would be the first step in the dehydration of cyclohexanol in sulfuric acid? OH
PRACTICE: A bimolecular nuclephilic substitution (S N 2) is
21
USF - ORGANIC CHEMISTRY I - PROF. FIELDS PRACTICE TEST: ACS ORGO 1 PRACTICE TEST PRACTICE: Which is the order from fastest to slowest for the rates of the SN2 reactions of these alkyl bromides with CH 3 S / DMSO? 22
USF - ORGANIC CHEMISTRY I - PROF. FIELDS PRACTICE TEST: ACS ORGO 1 PRACTICE TEST PRACTICE: Which of the mechanistic steps shown is not a reasonable one in the mechanism to describe the formation of 2-methyl-1-butene by dehydration of 3-methyl-2-butanol? PRACTICE: Which is the weakest nucleophile? 23
USF - ORGANIC CHEMISTRY I - PROF. FIELDS PRACTICE TEST: ACS ORGO 1 PRACTICE TEST PRACTICE:

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture