Question

Three reactions between a Grignard reagent and a carbonyl compound are given below. Draw the main organic product for each reaction and indicate if H+ or H- is needed to complete each reaction. (The starting material structures are provided in the answer fields as a starting point for your drawings.)

Three reactions between a Grignard reagent and a carbonyl compound are given below. Draw the main organic product for each reaction and indicate if H+ or H- is needed to complete each reaction. (The starting material structures are provided in the answer fields as a starting point for your drawings.)

Answer 1

Concepts and reason

The reagent which donates electrons and undergoes the formation of a new carbon – carbon bond is known as a Grignard reagent. Grignard reagent is an organometallic reagent with a formula. Here, represents alkyl group or aryl group, represents magnesium, and represents halogen. In this reagent, (alkyl group or aryl group) acts as nucleophile.

Fundamentals

In ketones, Grignard reaction undergoes two steps:

1)Nucleophilic attack

2)Protonation

Example:

In acid chlorides and ester, 2 equivalents of Grignard reagent react and form a new carbon – carbon bond. Then, this reaction undergoes nucleophilic attack twice cleavage of the leaving group occurs. This reaction proceeds in four steps:

1)Nucleophilic attack.

2)Removal of a leaving group.

3)Nucleophilic attack.

4)Protonation.

Example:

Part 1

Part 2

[Part 2]

Part 2

Part 3

Ans: Part 1