Design a multistep synthesis to show how the following compoun...

Question

Design a multistep synthesis to show how the following compounds can be prepared from the given starting material:

d. Chemical reaction diagram showing the conversion of a cyclohexane to a diol with hydroxyl groups.

Accepted Answer

Hey, everyone and welcome back to another video. Today, we're going to propose a synthetic approach to convert the following starting material into the desired product. The starting material is cyclopse and the desired product is trans one comma two cyclopse dial. We have to recall that because al canes including cy al canes are significantly unreactive. We always want to make sure that we convert them into more reactive alky ha lights. And specifically because Cyclopse is symmetrical, all of the hydrogen atoms are equivalent and we can replace one of them with say bromine or chlorine if you wish. And for that purpose, we're going to use the free radical halogen nation in which the bromine molecule is added in the presence of light so that we can observe the free radical hallage nation and form the the desired alky halite. Now, if we think about the formation of a trans one comma two dial, that's the final product. We have to remember that it's possible to get the dial out of any peroxide. So we can say that it will be formed from oxides. If we want to form an oxide, we want to have an alkene to begin with. So why don't we convert our alky halite into an ALK? And for that purpose, we want to use and e to elimination because we have a secondary substrate so that we need to use a strong base, which would also be a poor nu phy because we don't want to have substitution products. And if we choose a hysterical hi base such as TBI tox side, which is our classical bases that is hysterically hindered and also a strong base. It will not produce substitution products. And the predominant major product will be the elimination product so that we are going to produce an alkene. And there is only one product that we can form because we have two equivalent beta hydris to be removed. And that's how we are forming an king. Just in case you're wondering, we are taking one of the equivalent beta hydrogens, the oxide comes in and captures that proton. Then we are forming a pi bond followed by the loss of the leaving group when we have our alkin formed just as we said, we can form the diol out of an oxide. So let's recall that we can actually use a per acid or peri asset. In a general case, we can say that that's R C O 00 H or simply R C 03 H, any kind of oxy acid will allow us to convert the al into an oxide. So we are breaking the pi bond and we are forming our epoch side, you may draw two wedges or two dashes depending on the direction that you're looking at your compound. You can always rotate it. And you will notice that oxygen will be pointing down for the purposes of this problem. We are just going with two wedges. And finally, just as we said, if we want to form a trans one comma two dial, we want to make sure that we are using our oxide and we know that we can simply use a backside attack at one of our carbon atoms. So if we choose hydroxide to be our nuclear file, because the two carbon atoms are equally substituted. And in basic conditions, we are going to attack the less substitute deposition. It doesn't matter which one we attack, we will just have two possible products. So hydroxide will essentially attack the electro filic carbon, which will result in an inversion of configuration. So that means if we want to have a wedge or the first wage group, then we actually need to attack the other position, right? Because in this reaction, we are forming a pair of in an humors, there are two positions that can be attacked. So during the attack and the loss of the leaving group, we are forming the al oxide N I M let's throw it out. So that would be our intermediate. OK. And now we understand that we are going to have Al Cox So we have our wedge and oxygen with a negative charge pointing up. And because we have an inversion of configurations due to the backside attack, the age group will be pointing down. And finally, we want to perform the protonation step because we want to form a dial. So we are going to use water. And if we draw a water molecule, we are going to capture the proton and restore the basic conditions. So that's how, that's how we get our final dial where one of the alcohol group is spun up. And the other one is pointing down note that we have not, not drawn the in anti humor form because we are only interested in one of the two in anti. But we also want to make sure that for the previous arrow, we include that we want to use hydroxide and water. Although it should be apparent for us that we're using an aqueous solution of hydroxide. So there's plenty of water. We are also going to label the al oxide and is our intermediate because it's not actually part of our scheme, we have only thrown it for the purposes of understanding the problem. And now that we have our final synthesis, we are ready to review the steps in the first step. Cyclopse is treated with bromine in the in the presence of light using free radical halation to form an kill bromide, which is then treated with TBI dioxide to perform an elimination reaction E two and form cyclone cyclone is treated with a perox acid to form an oxide which can then undergo the base catalyzed ring opening from any side. So we can have a pair of in an tumors. And we are considering just one of them in the base catalyzed ring opening. We are considering the nucleic attack at the electro pic center followed by the loss of the leaving group. So we have an inversion of configuration due to the backside attack nature of the mechanism. The intermediate or the oxide and iron formed is then proton by the water molecule to produce the final trans one comma two dial. Thank you for watching and I hope to see you in the next video.

Design a multistep synthesis to show how the following compounds can be prepared from the given starting material:
d.

Key Concepts

Radical Reactions

Hydroxylation

Multistep Synthesis

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