When the three benzaldehydes shown below were exposed to HCN under identical conditions it was found that the equilibrium constants, K, for the three cyanohydrin formation reactions were different. Based on principles that govern equilibrium processes for reversible carbonyl addition reactions, place the K values for the three reactions in ascending order (smallest to largest). Briefly justify your answer. (Hint: Recall that electron deficient carbonyls tend to react faster with nucleophiles and have larger equilibrium constants for the addition reaction.) H X + HCN pH ~9-10 X = H, NO2, OCH 3 OH H HCN X

When the three benzaldehydes shown below were exposed to HCN under identical conditions it was found that the equilibrium constants, K, for the three cyanohydrin formation reactions were different. Based on principles that govern equilibrium processes for reversible carbonyl addition reactions, place the K values for the three reactions in ascending order (smallest to largest). Briefly justify your answer. (Hint: Recall that electron deficient carbonyls tend to react faster with nucleophiles and have larger equilibrium constants for the addition reaction.) H X + HCN pH ~9-10 X = H, NO2, OCH 3 OH H HCN X

Organic Chemistry

9th Edition

ISBN:9781305080485

Author:John E. McMurry

Publisher:John E. McMurry

Chapter19: Aldehydes And Ketones: Nucleophilic Addition Reactions

Section19.SE: Something Extra

Problem 28VC

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