Question

Pick One. Give the complete, detailed mechanism of one of the three following reactions. Be sure to include an explanation of the regiochemistry and stereochemistry of the product. HEC OP НОВ KCN NC HC Br HEC KOH

Answer 1

DATES OH И с и HOBry All By giles 11 When addition alkene reacts with Hobo it of HOBY to c=cbond. Ho Br is formed by mixture of Br , & H2O. 2) Regioselectivity He is added to carbon which is more substituted i.e. contain less number of hydroge & Bro added to carbon which is less substituta Mechanism OH OH ho. 7" BY Bromonium on, ज 3) In 1st step formation of bromonium son talks plance 2) Then in 2nd step attack of ot takes place hom opposited side of bromonium ion therefore, on 4 Br have opposite stereochemishy 3) It follows SN₂ mechanism." opposity stereochemistry

2) A KIN NG M I 1) When alkyl halide treated with potassium Inibile KCN, it undergoes SN2 mechanism (2) Alkyl halide is converted into alkyl nibile ces product. 3 Since it follows SN2 mechanism, stereochemisty of reactant is changes in stereohemidy. of producto 4) Bez attack of nucleophile CNO, & departure of Bro taks place simultaneonly. 5) Nucleophile che attacks from backside of LG BrO due to lees steric hindrance Mechanism :- RN NCH SN2. OP BT SO inversion of configuration.

DATEN Haf Hzc in ale. kol 1) When alkyl halide heated with alc. kot it undergoes elimination reaction y (2) It undergoes dehydrohalogenation reaktin 3) kot acts as base, it abstracts, B-hydrogen hom alkyl halide, & gives alkene as product, by elimination of Bre, . Mechanism. nanis Br figurno OH la cha k Br + H20. of 4) The B-hydrogen I antiperi planer to I hearing each other. group are