Question

Question:What products would be formed from the preceeding reaction if the carboxylic acid group were not protected?

Short answer

Answer

Product obtained in the reaction is 2-oxohexanedioic acid.

Step-by-step solution

Effects of protection in the yielding  of compound

Protection of a particular group in a compound leads to decrease in its yield. This is because protection and deprotection of a group adds two more steps in synthesis. So, there will be decrease in the yield of final product.

Preparation of 2-oxohexanedioic acid

Following product will be formed, if the carboxylic acid group were not protected:

Preparation of 2-oxohexanedioic acid

In this reaction carboxylic acid group is not protected by any of reagents. In that case 4-hydroxybutanoic acid is treated with thionyl chloride gives a product in which Cl is substituted instead of OH groups.The synthesized product on reaction with CN gives 4-cycanobutanyol cyanide which on reaction with acid hydrolysis gets the final product 2-oxohexanedioic acid. Thus, both OH groups converted to COOH groups.