Question

(16) 6. Deuterium is the isotope of hydrogen of mass number 2, with a proton and a neutron in its nucleus. It is often designated 2H, or D. We have seen that the chemistry of deuterium is nearly identical to the chemistry of hydrogen, except that the C-D bond is slightly (1.2 kcal/mole) stronger than the C-H bond. a) Propose (show) a mechanism to explain each product in the following reaction: CH2-CHCH CH CH CH3 CH3 CH CH3 KOH + OH Br alcohol

Answer 1

(a) KoH 1 OH can or a is a base, which gives act as a base mea Nucleophile. e, which gives a base, means on long. boton acceptor is When It Acts as a base, elimination Booduct is obtained Booduct is When It Acto Acts ap a . as a Nucleophile, Nucleophile, " substitution Boduct is substitution it - OHO CH, -CH -CH CH-CH-CH₂ - elimination base substitution Br * Product o OnO THE CH₂-CH-C1 -CH=CH 2 ch - CH1 CH² 20 L Cer c hio - Elimination Product 6 This is because, During Elimination, C-D bond has to be broken. which requires 1.2 kcal/mose energy than Required to break a C-H bond. While In substitution, No C-D bond breaks This is why Elimination Rate is slowed but substitution Rate is unchanged. Scanned with CamScanner