190 likes | 627 Views
Acid Halides from Carboxylic Acids. Synthesis of Acid Halides. SOCl 2 = thionyl chloride PCl 5 can also be used. Problems. Give the major product for the following reaction:
E N D
Synthesis of Acid Halides • SOCl2 = thionyl chloride • PCl5 can also be used
Problems • Give the major product for the following reaction: • Draw the products you would get from reacting the following molecule with PCl5. What product would you obtain from reacting it with PBr3?
Anhydrides from Carboxylic acids • Anhydride = “without water” 20.9 Conversion of Carboxylic Acids into Acid Chlorides and Anhydrides
Problem • The second reaction on the previous page happens through a nucleophilic acyl substitution reaction. Draw the mechanism. • What product might you get upon heating of succinic acid?
Reduction of Carboxylic Acids • The powerful reducing agent LiAlH4 is required • NaBH4 does not reduce carboxylic acids • The overall sequence for reduction is summarized as: 20.10 Reduction of Carboxylic Acids to Primary Alcohols
Problems • Draw the reactant that forms the following product upon reduction with lithium aluminum hydride: • How might you prepare 2-phenylehtanol from benzyl bromide? More than one step is necessary.
Decarboxylation of Carboxylic Acids • Decarboxylation: The loss of CO2 from RCO2H • Most ordinary carboxylic acids do not participate, but the following types do: 1. b-keto acids 2. Malonic acid derivatives (diacids) 3. Carbonic acid derivatives 20.11 Decarboxylation of Carboxylic Acids
Decarboxylation from b-keto acids 20.11 Decarboxylation of Carboxylic Acids
Decarboxylation from Malonic Acid Derivatives • This reaction also does not occur in base
Decarboxylation of Carboxylic Acids • Decarboxylation from carbonic acid derivatives
Problems • Give the products for the following reactions: