Which of the structures shown cannot be a nucleophile? II III IV II III IV Which of the structures shown is the most stable cation? II III IV II III IV Indicate which pattern of arrow pushing it is involved in the reaction step shown. proton transfer loss of leaving group nucleophilic attack rearrangement Melphalan, a drug used in chemotherapy, reacts with itself in the body before binding with its target, as illustrated in the mechanism below. Which two patterns of arrow pushing are seen in this reaction? I. proton transter II. loss of leaving group III. nucleophilic attack IV. rearrangement land II I and III II and III III and IV Current Attempt in Progress What is wrong with the mechanism shown? There is no leaving group, so there should be no arrows. The arrow should be removing a proton from the H2O group. An arrow is also needed to indicate the loss of the leaving group. The arrow indicating the formation of the CBr bond (nucleophilic attack) should start at the bromide anion. Identify the sequence of curved arrows (electron movement) in the steps of the reaction shown. proton transfer, proton transfer, nucleophilic Attack proton transfer, loss of leaving group nucleophilic attack, proton transfer, loss of leaving group proton transfer, nucleophilic attack, proton transfer Which of the following mechanisms correctly uses curved arrows to show the movement of electrons? OH2 II B III IV v