Question

What is the order of reactivity for acid-catalyzed dehydration?

Answer 1

The order of reactivity for acid-catalyzed dehydration of alcohols to alkenes increases from primary to secondary to tertiary alcohols. Nucleophilic substitution reactivity among carboxylic acid derivatives follows the order from amides to acid chlorides.

Step-by-step explanation:

The order of reactivity for acid-catalyzed dehydration of alcohols to alkenes typically follows the trend based on the structure of the alcohols. Primary alcohols (such as CH3CH2OH) are generally less reactive than secondary (such as (CH3)2CH-OH) and tertiary alcohols ((CH2)2C-OH), which are more prone to dehydration. The presence of a catalyst facilitates the removal of the OH group from the alcohol carbon atom and a hydrogen atom from an adjacent carbon, leading to the formation of an alkene and water.

Reactivity in nucleophilic substitution reactions among carboxylic acid derivatives follows this order: amides (R-C-NH2) < esters (R-C-OR) < anhydrides (R-C-O-C-R) < acid chlorides (R-C-Cl). As such, a reactant higher in the order can easily be converted to a lower one but not normally in reverse.

Answer 2

The order of reactivity for acid-catalyzed dehydration is tertiary alcohols > secondary alcohols > primary alcohols.

Step-by-step explanation:

The order of reactivity for acid-catalyzed dehydration is based on the stability of the intermediate carbocation formed during the reaction. The more stable the carbocation, the faster the dehydration reaction. Generally, tertiary carbocations are the most stable, followed by secondary, and then primary carbocations. Therefore, the order of reactivity for acid-catalyzed dehydration is tertiary alcohols > secondary alcohols > primary alcohols.