Question

8. Draw the structures of the products P1 and P2 for the two S2 reactions shown. Make sure to indicate the stereochemistry in the products correctly! How will the rate of these reactions change when the concentration of the nucleophile is cut into half? 7 --- aparen --- ^ Vorong po pong seconda con "Snö oom opo con

Answer 1

S_N2 Reaction:

S_N2-Substitution nucleophile second-order reaction. S_N2 reaction requires strong nucleophile and the nucleophile attack them from the backside of the leaving group. So the invention of stereochemistry takes place in the product. For example, If you take the R-isomer as a starting material you will get the S-isomer in the product.

Rate of the reaction S_N2 depends upon the both reactant structure and incoming nucleophile strength.

Mechanism:

(The mechanism shown in the below image please go through it.) In the first reaction nucleophile attack from the backside of bromine which will give the inversed product. In the second reaction leaving group in the below plane so incoming nucleophile approach from the above plane. So in the product nucleophile occupy the above plane.

Correct answer; option C   

c. BE P1 P2

P Bv Br! Sady SN2 HH BY W Soz - back side attack Р) SNZ - Invertion of Stereo chomisty ----BY H H Transition State Back side cutlock ON SN2 SNZ -back sick attack P2 SN2 - Invertion of Stereohomistry

   Rate of the reaction S_N2 depends upon both reactant structure and incoming nucleophile strength. So if you decrease the nucleophile concentration cut into off, It will definitely decrease the rate of S_N2 reaction (rate of reaction decrease approximately half).