Question

1. In each of the following addition reactions (1) using arrows provide a mechanistic explanation of the course of the reaction (show transition state for concerted mechanism and intermediate for two-step mechanism); (ii) write the product/s of the reaction; (iii) name the reaction product/s. (4 x 5= 20 points) a. Sulfuric acid catalyzed hydration (addition of H:0) of 2-methyl-but-2-ene b. Addition of molecular bromine to l-methyl-cyclohex-l-ene c. Addition of hydrogen bromide to (3R)-2,3-dimethyl-pent-1-ene, present product/s through Fischer projection. d. Hydroboration (addition of BH3) of l-methyl-cyclopentene, show mechanism. Write next step in which the product of hydroboration reacts with H2O2 in the presence of NaOH, don't show mechanism. Name the final products only, don't forget the descriptors for chiral centers. e. Addition of hydrogenchloride to 1-chlorocyclobutene, prove stability of the intermediate product by showing resonance structure.

Answer 1

2 methyl-2-butanol 2 methyl but sene Mechanisme у ?де, we Bray c rey, K, 1, 2 dibrao - weby cydebecane 1, 2-cfibromo -i-methyleyccherone 23 di Mechanism) - gy CH3 BTT Mechanisme CH2 (2R 3R12 Booms 23dimethyl pentane.

CH3 o BH3 | A에 imethyl Cyclopentence NUM 2 methyl tey topentanal Mechange -BH2 T.5. sonaddinen | Hella Fon tot dichterocyclobutane Ich luncyclobutene

2 methyl-2-butanol 2 methyl but sene Mechanisme у ?де, we Bray c rey, K, 1, 2 dibrao - weby cydebecane 1, 2-cfibromo -i-methyleyccherone 23 di Mechanism) - gy CH3 BTT Mechanisme CH2 (2R 3R12 Booms 23dimethyl pentane.
a) sulfuric catalysed hydration of 2 methyl 2 butene gives 2 methyl2butanol

b)1 methyl cyclohexene on Bromine addition gives 1,2 dibromo1 methyl cyclohexene

C) HBr addition forms alkene to alkyl Bromide

d) Hydroboration gives trans product