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26 Organic Chemistry Solutions Manual Problem 3 Complete these mechanisms by drawing the structure of the products in each case. Br H NH₂ (a) ? 0 CI (b) 7 Purpose of the problem First practice in interpreting curly arrows and drawing the products. Once the arrows are drawn, there is no more scope for decision-making. You must draw the products. Suggested solution Just break the bonds that are being broken and make the bonds that are being formed. It's as simple as that, though you might straighten out the products a bit so that there aren't any funny angles. H (a) 0 CI + + CI Br Br + (b) NH₂ + Problem 4 Each of these electrophiles could react with a nucleophile at (at least) two different atoms. Identify these atoms and draw a mechanism for each reaction together with the products from each. H H H Ph Ph N P Ph D Me Me Purpose of the problem First practice in considering different possible reactions. One of the reactions might seem trivial but it isn't. Suggested solution In each case one of the electrophilic sites is an acidic proton. There is also an electrophilic π bond in each case or C=N⁺). We might as well use the same abbreviation (Nu⁻) for the nucleophile that we used in Problem 1. For the first case, we draw the two reactions separately. H H H H H + H H N N N N Nu + NuH Me Me Me Me Me Me Me Me Nu For the second case, it should be clear enough if we draw the two alternatives on the same diagram. Nu H H H Nu H 0 Nu ( + NuH 1