Question

(2) Diels-Alder reactions of a diene with a dienophile are known to undergo a concerted reaction. However, 2,3-Di- tert-1,3-butadene does not undergo Diels-Aider reactions. Explain 2,3-di-tert-1,3-butadiene (4) Propose mechanisms for the following steps 1 and 2. Slep 1 Step 2 Bry Br NaBH CH acetic acid (I) Using> as a symbol, rank the following alkyl bromides in order of decreasing reactivity. (6 pts) Br Cн,Br -Br (a) For hydrolysis by an Sy1 mechanism (b) For hydrolysis by an S,2 mechanism (c) The order of the hydrolysis rates of the alkyl bromides in 80 % E1OH in H0 is (CH),CBr> CH,Br CH,CH,Br > (CH,),сHBr. Explain (3 pts) (d) (CHCBr reacts at the same rate with F and H20 in substitution reactions even though F' has a net negative charge. (3 pts) Shows the mechanisms for the following transformations кови сны ковы hotne

Answer 1

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