Q19P - Organic Chemistry (Mcmurry)

Question

What is the stereochemistry of the pyruvate reduction shown in Figure 19-12? Does NADH lose its pro-R or pro-S hydrogen? Does addition occur to the Si face or Re face of pyruvate? (Review Section 5-11.)

Step-by-Step Solution

Answer

                            Addition pro R hydrogen of NADH occurs at the Re-face

Step1: NADH

NADH is a biologically important reducing agent and it donates to reduce carbonyl compounds. Pyruvate undergoes reduction and converted to (S)-lactate by using NADH and configuration at the chiral center is S-configuration

Step 2: Addition of pro-R hydrogen

The NADH loses its pro R hydrogen in the reduction of pyruvate and the addition of pro R hydrogen of NADH occurs at the Re-face of the pyruvate which is represented as follows:

                            Addition pro R hydrogen of NADH occurs at the Re-face