Q29-12P - Organic Chemistry (Mcmurry)

Question

Is the pro-R or pro-S hydrogen removed from citrate during the dehydration in step 2 of the citric acid cycle? Does the elimination reaction occur with syn or anti geometry?

Step-by-Step Solution

Answer

The Thermodynamic stability and kinetic lability are also mentioned.

1. Pro-R
2. Elimination occurs with antigeometry

To Prefix pro and tetrahedral atom

The Mobility of pro chirality is significant in biological chemistry and in organic stereochemistry.

The prefix pro means “before”, while chirality refers to a tetrahedral atom or center to which distinct groups are linked; In other words, a stereo center

Apply different groups covalently bonded

When a carbon atom is tetrahedral and has four distinct groups covalently bound to it, it is said to be chiral.

Although a SP² hybridised carbon atom that is stereochemically trigonal planar is not chiral, such a chiral molecule can be turned to a chiral centre with the right reaction.

Threfore, The Presented biological process sheds light on natures concepts of pro chirality.

All reactions occur with preferred stereo chemistry reaction centres, the entering and exiting groups or reactants and subtracts react in conformations and configyrations that are less crowded, sterically open(less crowded), and energetically most favourable, whether spontaneously or analytically(low energy) .