Choose the compound in the following pairs that undergoes E2 elimination at the faster rat...

Choose the compound in the following pairs that undergoes E2 elimination at the faster rate.

(a)

(b)

(c)

Sample Solution (a) A double bond is formed between C-1 and C-2 when either of the two compounds undergoes elimination. Bromine is lost from C-1, and H (or D) is lost from -2. A C —H bond breaks faster than a C — D bond; therefore E2 elimination is faster in CH3CH2CH2CD2Br than in CH3CH2CH2CD2 CH2Br.