Question

The nucleophilic addition reaction depicted below involves a prochiral ketone carbon atom reacting with a nucleophilic hydride ion source (e.g., LiAlH4 or \"H–\") and, subsequently, a proton source (e.g., H2O or \"H \"). Consequently, the reaction produces a racemic mixture of an alcohol. Finish drawing the structures of the products resulting from nucleophilic attack upon the front and back faces of the carbonyl group, being careful to specify the stereochemistry via wedge-and-dash bonds.

Answer 1

Answer – We are given the 3-methyl2-butanone and upon the reduction with LiAlH₄ there is formed alcohol, there are possible two side attack, form the back side and front side, so the when front side attack then the –CH₃ gets back the plane and H is above the plane and when attack from the back side then H gets below the plane and –CH₃ become above the plane. There is –OH in the plane. So the structures as follow –

front face H3C CH3 1.H 2.H СНЗ back face 1.H H3 2.H

Answer 2

front face H3C CH3 1.H 2.H СНЗ back face 1.H H3 2.H

Answer 3

"CH3 Front face ront face OH —Н Y CH3 (R)-3-methylbutan-2-ol 3-methylbutan-2-one Hydride anion attacks front face of carbonyl of 3-methylbutan-2-one to form (R)-3-methylbutan-2-ol "CH3 Back face 3-methylbutan-2-one (S)-3-methylbutan-2-ol Hydride anion attacks back face of carbonyl of 3-methylbutan-2-one to form (S)-3-methylbutan-2-ol