Given that the treatment of α-bromoacetophenone, obtained from acetophenone by bromination, with NaBH 4 yields an epoxide . The structure of the epoxide is to be shown and its formation is to be explained. Concept introduction: The nucleophilic attack attack of the hydride ion on the carbonyl carbon of the bromoketone and the following internal nucleophilic attack by the negatively charged oxide ion and to eliminate a bromide ion will lead to the formation of the epoxide. To give: Given that the treatment of α-bromoacetophenone, prepared from acetophenone, with NaBH 4 yields an epoxide. The structure of the epoxide is to be shown and its formation is to be explained.

Question

Following is a retrosynthetic analysis for the synthesis of the herbicide (S)-Metolachlor from 2-ethyl-6-methylaniline, chloroacetic acid, acetone, and methanol. CI OMe OMe OMe 'N' HN N CI. + НО, Chloroacetic acid (S)-Metolachlor 3 NH2 CI + MEOH OMe Acetone Methanol 2-Ethyl-6-methylaniline Show reagents and experimental conditions for the synthesis of Metolachlor from these four organic starting materials. Your synthesis will most likely give a racemic mixture. The chiral catalyst used by Novartis for reduction in Step 2 gives 80% enantiomeric excess of the S enantiomer.

Answer 1

Question

Chapter 18.SE, Problem 68GP

Interpretation Introduction

Interpretation:

Given that the treatment of α-bromoacetophenone, obtained from acetophenone by bromination, with NaBH₄ yields an epoxide. The structure of the epoxide is to be shown and its formation is to be explained.

Concept introduction:

The nucleophilic attack attack of the hydride ion on the carbonyl carbon of the bromoketone and the following internal nucleophilic attack by the negatively charged oxide ion and to eliminate a bromide ion will lead to the formation of the epoxide.

To give:

Given that the treatment of α-bromoacetophenone, prepared from acetophenone, with NaBH₄ yields an epoxide. The structure of the epoxide is to be shown and its formation is to be explained.

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Following is a retrosynthetic analysis for the synthesis of the herbicide (S)-Metolachlor from 2-ethyl-6-methylaniline, chloroacetic acid, acetone, and methanol. CI OMe OMe OMe 'N' HN N CI. + НО, Chloroacetic acid (S)-Metolachlor 3 NH2 CI + MEOH OMe Acetone Methanol 2-Ethyl-6-methylaniline Show reagents and experimental conditions for the synthesis of Metolachlor from these four organic starting materials. Your synthesis will most likely give a racemic mixture. The chiral catalyst used by Novartis for reduction in Step 2 gives 80% enantiomeric excess of the S enantiomer.

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