Q29-51E - Organic Chemistry (Mcmurry)

Question

In glycerol metabolism, the oxidation of sn-glycerol 3-phosphate to give dihydroxyacetone phosphate is catalyzed by sn-glycerol-3-phosphate dehydrogenase, with NAD1 as a cofactor. The reaction is stereospecific, occurring exclusively on the Re face of the nicotinamide ring. Which hydrogen in the NADH product comes from sn-glycerol 3-phosphate? Does it have pro-R or pro-S stereochemistry?

Step-by-Step Solution

Answer

The glycerol metabolism and the oxidation can be predicted as follows. 

Step 1: Reaction diagram

The reaction which is similar to the reaction with ethanol can be drawn as,

Step 2: Glycerol metabolism reaction

The biologically enzyme-catalyzed reaction which involves prochiral centres along with stereospecificity. The deuterium substrate have shown in the glycerol metabolism reaction. The reaction which involves with oxidation of Sn-Glycerol-3-PO₄^3- to give DHAP and coenzyme. It can be catalyzed by the enzyme alcohol dehydrogenase and pro-R-hydrogen can be removed from ethanol. 

The entering of prochiral reacts with stereospecificity and even in the metabolism of biological reaction.