Predict the major product(s) for each reaction. Include stereo...

Question

Predict the major product(s) for each reaction. Include stereochemistry where appropriate.

a. 1-methylcyclohexene + Cl₂/H₂O

b. 2-methylbut-2-ene + Br₂/H₂O

Accepted Answer

Hey everyone and welcome back into this video. We are going to tackle the following problem for each of the following reactions determine the major product or products include stereo chemistry. In your answer, we are seeing two reactions number 11 muscle cycle pension reacting with chlorine over water. Number 22 metal pen to in reacting with blooming over water. We may essentially notice that if we examine these two reactions to al kins are reacting what a molecule of X. T. Where X. Is a halogen over water. And we may notice that if we remember these reactions are called the halo hydrant reactions in which we are forming halo high trends which in particular have an anti arrangements of acts and O. H. Now knowing this information, we essentially have the basis for our solution and we will think about these reactions as halo hydro information reactions. If we start with the first problem, we understand that we are starting with psycho fencing, we may draw a five member ring. Now we may place the position of the double bond anywhere and now supposing that this is position number one, we add a metal group and the reaction conditions are chlorine over water. Recall that the world first step in the formation of any halo hydrant is actually the production of clay roni um iron in this case. So we're using our pi bonds to create that claire oni umbridge. Let's draw it out. Now we have two possibilities right? We may either add chlorine above the ring or below the ring. Let's only look at one of the possibilities. But let's also keep in mind that we produce a pair of finance humors. If we think about the wedges indicating that chlorine is above the ring, then we have chlorine with a formal positive charge because now it forms two bonds and then there is that original methyl group which is now pointing down. Right? So this is our first intermediate again. Remember that we have another possibility where we draw two dashes here, right? But we will only analyze one of the two structures. Now this is where water comes in, right? And we have to recall that water will attack a more substituted position comparing the two carbon atoms bonded to court. And we noticed that this is a more substituted position due to the presence of the methyl group. So we have the nuclear attack had that carbon which is the backside attack. The backside attack implies that there will be an inversion of configuration at that center. So if we think about our product, we also have to recall that in the stuff, we will be d protein eating it, right? Because our goal is to produce in a wage group and alcohol group. Right? So we may indicate that we are also deep rotating it. You may either deport innate it with another molecule of water or the chloride and ion which had been formed in the in the first step. However, it's not so important. Let's just think about the stereo chemistry here. And let's keep in mind that it just deportation just takes place in the next step. We are just going to summarize it by minus H plus. Now, regarding the inversion of configuration, you may notice that because this bond was pointing up now the O. H bond will be pointing down so we will have a dashed bond. So we first of all redraw the five member dring. We understand that ohh will now be pointing down now chlorine was the leaving group. So nothing changes regarding this bond, we will still have chlorine pointing up which is consistent with our analysis, isn't it? We noticed that the arrangement is anti because one bond is pointing down, the other one is pointing up. And that means the original metal group will now be pointing up over here. So we got our first product. Well done. Remember that? We also get it in and humor. So we can say plus E. M plus it's an anti matter because once again, there are two ways to add that chlorine above or below the ring. The attack will still take place at the same carbon. But we will have two possibilities to form a pair of finance farmers right? Meaning, there will be two products, We have only drawn one structure if you wish to draw, it's an anti armor, simply change your configurations to opposite ones O H would be on a wedge and chlorine would be on a dash. Right? So this will be our first product or products for reaction number one. And if we think about reaction number two two metal 10 to in So we are drawing a five member chain at position number two. We have a double bond to in and two metal meaning we're adding a methyl group. The reaction conditions are very similar because we are treating that elkin with bro mean over water. So we have ruminated water. In the first step, we are forming the broad ammonium bridge very similarly to what we saw before. So we may use this as our basis and again, there are two possibilities to add it either above this carbon carbon bond or below it. Right? So we may just draw one of the two structures in particular this ceremony. Um Kay Ryan, we will see two metal groups here, one pointing out the other one pointing down and right here we will see a hydrogen atom pointing down, right? And there will be an ethyl group pointing up. Let's throw it in a different direction for complete clarity. So that would be seized two CS 3. So this is our intermediate, that's pra monium bridge. And then the next step we have the nuclear attack step between the two carbon atoms. We want to choose the one that is more substituted and this is the carbon that we want to use because it has two metal groups. The other carbon only has one ethyl substitution. So we are going to attack the more substituted position using that backside attack. So because it's a backside attack again we have an inversion of configuration but in particular this carbon is not even Cairo if you notice there are two equivalent metal groups meaning we are only interested in that carbon which is the only Cairo carbon atom. And as we said before we are producing a pair of finance commerce. So we will either place blooming on a wedge or a dash to indicate the presence of that inanimate pair. And if we use the shorthand notation for the deep protein nation step we will just say minus H plus we may now simply draw a five member Chain 2345. We may see that there was a metal group and now there isn't a wage group so we had an O age group and a metal substitution And at the following position in particular position, number three we are adding roaming and in one of our structures it will be on a wedge pointing up but we will also produces an anti MERS we are going to say plus it's an antenna right in the other structure to be pointing down on a dash. So that will be our next structure. We may label this is our product or products for reaction number two and we may simply conclude that the correct answer to this multiple choice question is C However, if you have any questions, don't have to leave your comment down below in the comments section, thank you for watching, and I will see you in the next video.

Predict the major product(s) for each reaction. Include stereochemistry where appropriate.
a. 1-methylcyclohexene + Cl₂/H₂O
b. 2-methylbut-2-ene + Br₂/H₂O

Key Concepts

Electrophilic Addition Reactions

Stereochemistry in Reactions

Markovnikov's Rule

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