Ch. 10 - Addition ReactionsWorksheetSee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins
Addition Reaction
Acid-Catalyzed Hydration
Epoxide Reactions
Ozonolysis Full Mechanism
Oxidative Cleavage
Alkyne Oxidative Cleavage
Alkyne Hydrohalogenation
Alkyne Halogenation
Alkyne Hydration
Alkyne Hydroboration
Additional Practice
Thermodynamics of Addition-Elimination Equilibria
Stereospecificity vs. Stereoselectivity
Oxymercuration-Reduction Full Mechanism
Hydroboration-Oxidation Full Mechanism
Haloether Formation
Simmons-Smith Addition Mechanism
Regiospecificity of Acid-Catalyzed Ring Openings
Anti Vicinal Dihydroxylation
Ozonolysis Retrosynthesis
LiBr and Acetic Acid for Anti Vinyl Dihaldes
Addition Reagent Facts
Predicting Stereoisomers of Addition Reactions
Addition Missing Reagent
Addition Synthesis
Addition Texas Two-Step
Addition Multi Step
Addition Retrosynthesis
Addition to Concave vs. Convex Rings

In this reaction, we learn how to use certain agents to add diols to a double bond. This is also known as the 1,2-syn diols reaction. 

Concept #1: General properties of syn vicinal dihydroxylation.


So now I'm moving on to yet another addition reaction and this addition reaction is going to be one that adds two alcohols to the same double bond and it's going to do it all in one step. This reaction is called syn vicinal dihydroxylation. So how does this work?
Basically, we have these two very special reagents. We have potassium permanganate and we have osmium tetraoxide, this is KMnO4 and OsO4, that are both highly capable of adding oxygens to double bonds.
Now it turns out that this mechanism, you're not going to need to know the whole thing, but what you do need to know is you need to know what the end product is going to look like. As you can see, it's really easy. All we have is a double bond. We add one of these two reagents. It doesn't matter which one. Sometimes you're going to see catalytic NMO. That's just a catalysis that sometimes comes up, sometimes it doesn't. Don't worry too much about it.
And what you're going to get at the end is what we call diols. Why? Because there's two alcohols on the same molecule. They have a vicinal relationship. What's vicinal mean? It just means that they're next to each other. They have a one-two relationship. And they are syn to each other or they're cis. That means that the reaction is syn.
So how does this actually work? The reason this works is because potassium permanganate and osmium tetraoxide both have a very, very similar structure where it's basically one central atom surrounded with as many oxygens as possible.
Now the way that I like to think of this, maybe just to make it really kind of fun, is I kind of visualize that these look like spaceships. So this is like a flying saucer. And there's a flying saucer. And there's a little cockpit here with an alien inside. But of course, he's got four arms because aliens don't have the same amount of arms as we do. And whatever.
We've got these UFOs and what do they do? Well, they fly down to earth and they go attacking double bonds. So the UFO is like coming. It's swooping down on the double bond. And it decides I'm going to leave humans a gift. I'm going to leave this double bond a gift. What it's going to do is it's just going to add an oxygen to both sides of the double bond. It's basically going to take one of the oxygens here, one of the oxygens there and add them to both sides leaving a diol at the end.
Please, do not tell your professor that I just told you that. I sound like a retard telling you this mechanism where there's like a spaceship and it's abducting cows or whatever. I don't know. I'm just making shit up at this point. But I'm just trying to help you guys remember because I know there's been a lot of reagents today, why these reagents are special and how you could think of what they do. So they're going to leave two alcohols behind and they're going to take off back into space.
Now if you do want to know the mechanism really quick. I am going to show you the first step. You don't need to know the whole thing. But it's going to look like this, where if you have a double bond and you have let's say we're using osmium tetraoxide, so a double bond. What's going to happen is you're going to get a cyclization reaction where my – and there's a methyl there. I'm sorry. Where my double bond grabs one of the O's. These electrons go down onto the osmium and then these electrons go and make a bond to the double bond.
So what winds up happening is that we get the cyclization reaction, you wind up getting two alcohols at the end and then you're OsO4, obviously it's missing two oxygens. That thing just leaves and it goes back into space. So you might need to know the first step, but regardless, you're never going to need to know the whole mechanism, at least I've never seen that. And I've been teaching orgo for a very long time at a lot of universities.
So let's go ahead and do a multi-step reaction here. And what I want to do is just literally have you guys go ahead and try to figure this out by yourself and then I'll go ahead and jump in. 

General Reaction:

You don’t need to know this entire mechanism, but I would suggest knowing the first step:

Example #1: Predict the product for the following multi-step reaction. 

What is the major product of the reaction drawn below? For clarity, the other enantiomer was not drawn for those labeled as racemic.   
Suggest a synthetic scheme for the following transformation:
Give the product, or products, including stereochemistry of the reaction of (Z)-3-methyl-2-pentene with the reagent below. If the products are a pair of enantiomers, you need to draw only one and state that the other enantiomer is formed.  OsO4 / NaHSO3
Draw the organic product of the following reaction, being mindful of stereochemistry. If the reaction forms two enantiomers, draw one of the two enantiomers.
Consider the strucutres below and answer the following questions.  d. Which comopunds will each form a pair of enantiomers by reaction with OsO4 / NaHSO3 ?
Which set of reagents could be used to effect this conversion?
Provide the major product for the alkene reaction below. 
Show the appropriate arrow pushing on the left side of the equation and write the structre after the first immediate step on the right side. (please re-write the reagent where necessary)
Predict the organic products of the following reaction. Show stereochemistry clearly. The (R) of (S) designation for each stereocenter carbon atom is specified adjacent to the answer box. Please draw the products accordingly.
Predict the organic product(s) of the following reaction. When appropriate, be sure to indicate stereochemistry. If more than one product is formed be sure to indicate the major product, if stereoisomers are produced in the reaction be sure to indicate the relationship between them. Draw all answers in skeletal form. 
Predict the product of the reaction: 
Show the appropriate arrow-pushing on the left side of the equation, and show the result after the first immediate step on the right side of the equation. (re-write the reagent where necessary!)
What will be the major product of the following reaction? Pay careful attention to the stereochemistry of the product.
Draw the major organic products for this reaction. Show stereochemistry in your structures. Do not include lone pairs. Then check the box to indicate the stereochemical relationship of the products
Draw the structural formula for all the alkenes with the indicated molecular formula that, without undergoing a rearrangement, produce the compounds shown as major products. 
Draw the structure resulting from a reaction of osmium tetroxide (OsO4) and hydrogen peroxide (H2O2) with the following alkene.
Draw the product that's formed when 1,2-dimethylcyclohexene reacts with KMnO4 in basic aqueous solution. Use the wedge-and-dash bonds to show the correct arrangement of the substituents in the product.
Draw the two products that are formed when the compound shown below reacts with KMnO4 in basic acidic aqueous solution.
Consider the following reactions. Indicate how many stereoisomers you expect to be formed in the reaction, and specify what kind of isomers you expect.
Draw the product that's formed when 1,2-dimethylcyclohexene reacts with KMnO4 in basic acidic solution.