Q 20E - Organic Chemistry (Mcmurry)

Question

Question: One of the steps in the biosynthesis of uridine monophosphate is the reaction of aspartate with carbamoyl aspartate, followed by cyclization to form dihydroorotate. Propose mechanisms for both steps.

Step-by-Step Solution

Answer

The mechanism for the reaction is:

Step 1: Definition of mechanism

The sequence of elementary steps by which a chemical reaction occurs is defined as the mechanism.

Step 2: Explanations

The reaction occurs by the removal of the phosphate group along with the water molecule to give rise to dihydroorotate. The removal of the water molecule leads to the cyclic addition of the carbamoyl aspartate to give rise to dihydroorotate.

The reaction of aspartate and carbamoyl phosphate gives rise to dihydroorotate.

The mechanism for the reaction is: