Question

Draw the products formed when A or B is treated with each reagent. In some cases, no reaction occurs.

1. NaBH₄, CH₃OH
2. [1] LiAlH₄ ; [2] H₂O
3. [1] CH₃MgBr ; [2] H₂O
4. [1]C₆H₅Li ; [2] H₂O
5. Na₂Cr₂O₇, H₂SO₄,H₂O

Short answer

Answer

The products formed when A is treated with each reagent are shown below:

e. No product is formed by Na₂Cr₂O₇ since it oxidizes aldehyde groups to carboxylic acids.

The products formed when B is treated with each reagent are shown below:

e. No product is formed by Na₂Cr₂O₇ since it oxidizes aldehyde groups to carboxylic acids, and also primary alcohols and secondary alcohols to aldehydes and ketones, respectively, which are not found in the structure.

Step-by-step solution

Step-by-Step Solution Step 1: Function of organolithium reagent

When you use lithium, the halogen and metal exchange to form the organolithium reagent and function as a nucleophilic agent and a base.

Function of Grignard reagent

When Mg is used, it gets inserted into the carbon-halogen bond to form the Grignard reagent and function as a nucleophilic agent and a base.

Function of metal hydrides

Metal hydrides such as NaBH₄ and LiAlH₄are strong reducing agents that can reduce an aldehyde to primary alcohol and a ketone to secondary alcohol.

Function of  Na2Cr2O7

Na₂Cr₂O₇ is a strong oxidizing agent that oxidizes aldehydes to carboxylic acids, and primary and secondary alcohols to aldehydes and ketones, respectively.

In Na₂Cr₂O₇ , the Cr lies in the +6 oxidation state and hence undergoes over-oxidation.

Considering all the steps, the products formed when A is treated with each reagent are shown below:

e. No product is formed byNa₂Cr₂O₇ since it oxidizes aldehyde groups to carboxylic acids, and also primary and secondary alcohols to aldehydes and ketones, respectively, which are not found in the structure.

The products formed when B is treated with each reagent are shown below:

e. No product is formed by Na₂Cr₂O₇ since it oxidizes aldehyde groups to carboxylic acids.