Predict the major products of the following reactions. Include...

Question

Predict the major products of the following reactions. Include stereochemistry where applicable.

(a) 1−methylcyclohexene + BH₃⋅THF then H₂O₂, OH^–

Accepted Answer

Welcome back everyone in today's video, we're looking at the problem which states for the following reaction determine the major products include stereo chemistry in your answer and we have a reaction between one methyl cyclo benzene boring and tetra hydro Furin and then that's followed by hydrogen peroxide and a strong base which is hydroxide. Now, when we look at this reaction, first of all, we have to notice that the reaction conditions in particular are boring in tetra hydro Furin followed by hydrogen peroxide in hydroxide. So we call such a reaction a hydro operation oxidation reaction. The first thing to recall is that whenever you look at the first condition of this reaction, we have boring forming a bond with tetra hydro ferrin. Now, if we look at the stop, this is really important because if you think about the structure of boring it's really reactive and it actually forms a dime er it's an equilibrium with die boring, which is where explosive and flammable. So we are using a stabilizing solvent which is, which in this case is tetra hydro Furin. So sometimes you may notice this reaction written as born comma tetra hydro Furin. You don't have to worry about tetra hydro ferrin acting as some sort of a substance in this reaction that essentially changes the outcome. It's essentially used to stabilize boring and to decrease the amount of dye boring that is formed in this equilibrium. Now going back to our reaction, we will start by drawing one metal cycle, panting. So we are going going to draw a cycle. Benzene ring. We may place a double bond within the ring at position. Number one, we have a metal substitute print. And this is one method cycle fencing. First of all we are adding boring and tetra hydro ferrin and then we have to recall that this is the anti more cognitive edition. What we may essential estate is that along this double bond we will be adding hydrogen and beach to. In other words, recall that because this is the ante markovic of addition, hydrogen will be added to a more substituted carbon. So we will be adding hydrogen and disposition and then the remaining part of the molecule which is B. H. To another position. Also recall that hygiene. The main reason for that is that hygiene is more electro negative than warren. S And therefore hygiene would be added to a position which could be stabilized more whenever you think about a potential carbo Karen here. So if a carbon Karen is formed at this position, it will be more stable because it will be a tertiary carbon Karen and therefore the partially negative hydrogen would be attached to that position. So it makes complete sense that this happens now we are ready to draw our intermediate But also recall that this is a syn addition. We are adding hydrogen in beach two in sin arrangements, meaning they both will be pointing either up or down. So we will have two possibilities to form our product. And the first reaction let's throw both of them. One of them will contain a ring. We will not have a double bond anymore. Let's suppose that the first product will indicate the presence of hydrogen and beach to both pointing up. So we will draw both of them on ledges That would be BH. two pointing up. That would be hydrogen pointing up. And as a result this metal group would be pointing down so we are ready to draw a death metal group pointing down. However, another instance is where we can add both of them pointing down because that would also be set an arrangement in which the two substitutions will be pointing in the same direction. So our second possibility is to get a product In which beach two and H are both pointing down. So we will draw them on dashes B H two hydrogen pointing down. And now the remaining method group will be pointing up so we may draw a wedge These are our two structures. For the first step we have our stereo chemistry and in the next step we're using hydrogen peroxide and hydroxide. So let's look at this part of the reaction. Each of these structures will undergo this reaction. So we will indicate the presence of H two to N. O H minus hydrogen peroxide and hydroxide. Now there are multiple steps in this part. So we are not worried about the mechanism essentially, we can just may state that hydroxide, the protein, it's peroxide and that attacks for and then we have an alcohol shift and so on. But the main takeaway from here is that you have to recall that essentially we are going to replace this beach to with O. H. And we will also have retention of stereo chemistry or retention of configuration at this position. If we stated more accurately we have retention of configuration in each of these is replaced with O. H. Let's not worry about the mechanism because it's a bit complex. So it just worked noticing that this is always the case and the second step of hydro operation oxidation. So we are going to draw our two products. We are going to draw our ranks. Let's start with the bottom substitution. So we have a muscle group pointing down now it's not really important to show that implicit hydrogen anymore. We primarily want to focus on this part and we now know that BH- two will be replaced by a wage in exactly the same configuration. It will be pointing up and the second product would have a methyl group pointing up and now beach too was pointing down. Therefore, O H would also be pointing down notice that we have formed a pair of finance humors. That's why it was really important to carefully look at the step and understand that there were two ways to add worrying to the double bond either up or down instant arrangement because depending on how you added, you will get two different structures which are in and emerge notice that they have opposite configurations for each carroll center. We have these two carol centers in this position and to carol centers. Over here we have opposite configurations for each center, and therefore they are in ann summers. These are our cheap products. And as you can see, the correct answer to this multiple choice question is the If you feel that you have any questions, don't hesitate to leave down down below in the comment section, and thank you for watching.

Predict the major products of the following reactions. Include stereochemistry where applicable.
(a) 1−methylcyclohexene + BH₃⋅THF then H₂O₂, OH^–

Key Concepts

Hydroboration-Oxidation

Stereochemistry

Markovnikov's Rule

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