(b) Consider the following two elimination reactions from substrates 6 and 8. EtO HO 6 L = H or D CH3 8 Question 4 continued. ● Br OPh base. L = H or D EtOH H₂O 7 CH3 9 Page 8 of 11 + + + + EtOL O Br HOL Pho d[6] dt = KH/KD = 7.1 - Kobs [6][ Eto d[8] dt ke/kD = 0.8 = The following observations have been made about these reactions: - Kobs [8][HO Question 4 continues on the next pag CHEM30211 . Both reactions are second order overall and are first order in both substrate an PT The formation of 7 from 6 shows a strong primary kinetic isotope effect, where the formation of 9 from 8 does not show a primary kinetic isotope effect. Dissolving deuterated 8 (L = D) in basic water also produces 8 (L = H) as a by product where the deuterium label has been lost. For each of these reactions draw a mechanism and explain how each is consiste with the observations above. In each mechanism, indicate the slow step.