Question

Write the products of the following sequences of reactions. Refer to your reaction roadmaps to see how the combined reactions allow you to "navigate" between the different functional groups. Note that you will need your old Chapters \(6-11\), Chapters \(15-18\), and Chapter 19 reaction roadmaps along with your new Chapters \(20-23\) reaction roadmaps

Short answer

Question: Based on the following step-by-step reactions, find the product formed after each step. Starting Compound: Benzene (C6H6) Step 1: Reaction with CH3Cl and AlCl3 (Friedel-Crafts Alkylation) Step 2: Reaction with Br2 and FeBr3 Step 3: Reaction with NaNH2 followed by CH3I

Step-by-step solution

Identify the Starting Material and Functional Group

Recognize the initial compound provided and its functional group(s). This information will be useful to understand which reaction pathways are possible and which one we need to follow. 2.

Recognize the Reagent

Analyze the reagent present in the step and determine what type of reaction it usually performs. This can be done with the help of reaction roadmaps provided in the chapters. Understand the mechanism of the reaction if needed. 3.

Predict the Product

Based on the reagent and mechanism, predict the product of the reaction. This product will be the starting material for the next step in the sequence. 4.

Repeat Steps 2 and 3 with Subsequent Reagents

Continue recognizing the reagents, understanding the reaction mechanisms, and predicting the products formed for each step in the sequence. Be aware of any side reactions or competing pathways and consider the conditions under which the reaction is performed. 5.

Verify the Final Product

Confirm that the final product is reasonable and follows guidelines from the reaction roadmaps. In order to perform this exercise correctly for a specific example, please provide the sequence of reactions and the starting compound.

Key concepts

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those compounds. Understanding functional groups is crucial because they help determine how an organic molecule will react under different conditions.

Every functional group has a typical reactivity pattern, which can be used as a signpost when navigating reaction roadmaps. For instance, an alcohol (\text{-OH}) group generally can be transformed into a good leaving group and then undergo substitution or elimination reactions. Carboxylic acids (\text{-COOH}), on the other hand, can be ugraded to more reactive acyl chlorides (\text{-COCl}) by treating them with reagents like thionyl chloride (\text{SOCl\(_2\)}).

In your organic chemistry course, you've learned about various functional groups across chapters 6-23, which include alcohols, alkenes, alkynes, carbonyls, carboxylic acids, and many more. By familiarizing yourself with these groups and their reactivity, you can tackle complex synthetic problems with greater ease.

Reaction Mechanisms

A reaction mechanism is a step-by-step description of the process by which reactants transform into products. It includes all the elementary steps, such as bond making and breaking, rearrangements, and electron transfers, that occur throughout the reaction.

Understanding mechanisms is vital because it allows chemists to predict how a molecule will behave under certain conditions. For example, a nucleophilic substitution mechanism, SN2, will proceed differently than an SN1 mechanism because the SN2 involves a single concerted step, while SN1 includes a carbocation intermediate.

Knowledge of mechanisms also helps in troubleshooting synthesis when unexpected results occur. It allows you to adjust conditions or reagents to steer the reaction toward the desired pathway. This is why recognizing the reagent, as mentioned in a textbook exercise, and knowing its common reactions, can be the key to mastering organic synthesis.

Organic Synthesis

Organic synthesis is the process of constructing organic molecules through a series of chemical reactions. The ultimate goal is to build complex molecules from simpler ones using the toolbox of reactions that involve functional group transformations.

In the context of your education, reaction roadmaps are incredibly valuable. They are visual schematics that outline possible transformations from one functional group to another, allowing you to plan and predict the steps in a synthesis scenario. As you gain proficiency, you will recognize patterns and become more adept at selecting the best sequence of reactions to attain the target molecule.

An essential aspect of organic synthesis is considering the conditions under which reactions take place, such as the solvent, temperature, and concentration, because these can drastically affect the outcome. This is tied to the concept of reaction mechanisms, as different conditions can favor different mechanisms.

Predicting Reaction Products

Predicting reaction products is often the heart of organic chemistry problems. It requires understanding both the properties of the functional groups involved and the specific mechanisms at play. When you accurately predict the product of each step in a sequence, it ensures that you truly comprehend the underlying chemistry.

The process begins with identifying the starting material's functional group, taking into account the reagent and the conditions. By applying known reaction mechanisms, you can predict the intermediate or final products. If multiple steps are involved, as in the provided textbook exercise, this process must be repeated for each stage.

For instance, treating an alkene with hydrogen and a metal catalyst will yield an alkane - a simple example of a hydrogenation reaction. Predicting is not always straightforward, though; some reactions may give more than one product, depending on the subtle nuances of the reaction conditions or the presence of multiple functional groups. As such, predicting involves a combination of knowledge and analytical thinking.