Question

7. Draw the structures of the products P1 and P2 for the two SN 2 reactions shown. Make sure to indicate the stereochemistry in the products correctly! What is the most appropriate description for the role of the polar aprotic solvent (DMSO) in each reaction? KCN NASH → P1 By → P2 DMSO DMSO For questions 7 - 10: to practice for the exam: draw the reaction-energy diagrams for these reactions, writing out the specific rate equations for each of the reactions. Draw the structures of the Transition States and provide the curved arrows to show a step-by-step mechanism for each of these reactions. This is the type of question you should expect on all future exams. A. DMSO solvates only the cation ( Kor Na') and thus increases the reactivity of the nucleophile in the SN2 reaction. The products are HS P2 B. DMSO solvates only the cation ( K or Nat) and thus increases the reactivity of the nucleophile in the S2 reaction. The products are HS P1 P2 C. DMSO solvates only the anion (CN or SH) and thus increases the energy and reactivity of the nucleophile. The products are HS P1 P2 D. DMSO solvates only the cation (Kor Nat) and thus increases the reactivity of the nucleophile in the S2 reaction. The products are HS P2 E. DMSO solvates only the anion (CN or SH) and thus increases the energy and reactivity of the nucleophile. The products are -UZ

Answer 1

Answer KON Dmso.: Nash Bay - HS DMSO A Diso solvates only the cahim K ar Nat and thus increases the teach*vity of nucleophile in swe reachcom. HS/ P2 These are the example ols SNP reachch. The sn2 seachom involves the backside attack of nucleophile. Therelore due to backside attacks ols nucleophile, the ophocally ach've substrate on SN2 teach on the bormation of product occurs with complete inversico os con laguration of deaving group containing Carbon atom. Its molecule has other chiral ceutes and then there stezeochemistry doesnot change. Only stereochenu'stry of Deaving group containing chical carbon atom is changed. in SNP reacheon (60% inversion of Conisiguration occurs. In Polar Aprohic solvent the rate of 5N2 reachºon is increases because in polar apoohºc solvent like omso, the solvent molecule solvate the canon only os corresponding nucleophile and nucleophile is completely free to attack, Therelsore rate of 5N2 reach cor is faster in aproba solvent. eig Nemo + omso Bonos Completely Free

Rate equabion of Spa Reach ou SN2 is bimolecular subsbtulion reacbco) · The rate of reaction u Rate = K2 [ Substrate ] [ KON] clepends on concentrahico of nucleophile as well as 23 Rate = K2 [ substrate ] [ Nash] concentrahicar os substrate Mechanism GON slow Iz S-Br Bo Backside attack os nucleophile T.S. solo afyalarla Back side altoel Rate equal on 1) Rate = ka ten] [kon] a) Rate = K2 [ty] (nlasu ]

Energy diagrams i 36 Tos + KCN | KBC - Reachico coordinate [comm] PE & Nash + NaBr - Reaches Coordinate