Predict the major products of the following reactions. a. propene + BH 3 ⋅THF b. the product from part (a) + H 2 O 2 /OH −

Hi everyone and welcome back in today's video. We are looking at the problem with reads for each of the following reactions determine the major products. Reaction number one. We have built one in reacting with boring and tetra hydro ferrin and reaction to we get the product from part one and reacted with hydrogen peroxide and hydroxide. Let's start by drawing the substrate for reaction one and it states that we have beat one in. So we are ready to draw our four carbon chain at position number one. As the name suggests we have in which means there is a double bond at that position butte one in has been drawn that's beat one in And now it reacts with boring BH three in a solvent which is called tetra hydro Furin. Tetra hydro Furin is a solvent here. You don't have to worry about as the main substance that will react in this reaction is boring itself and that's the hydro Furin simply acts as a stabilizing solvent, which favors the equilibrium between boring and it's timer towards boring itself because that's what we want to have. Now in the first reaction, we're essentially looking at our double bond and then we are showing an addition mechanism that would be addition. This edition follows the ante Markovic of rule, do you see the following reasons if you look at the structure of boring, it's actually planer so they destroyed properly. So that would be B H three, boring is interesting because hydrogen is more electro negative than born. So we have a partial negative charge for each hydrogen and partial positive charge for born itself. This is not usually the case, but it's important here and because hydrogen is more electro negative and therefore partially negative, it will be added to a more substituted position in particular at this position because here we have now killed substitution as opposed to this position where we only have two hydrogen atoms. So we will be adding hygiene in this position because this carbon can be are a positive charge better since it's more substituted. And the remaining part, which is BH two Will be added at position No. one So this is our molecule of boring. We were essentially just clearly showing the bond between one of the Hydrogen & Born. So beast is added that decision one and hydrogen is added at position number two. That said we are ready to draw our first product. We may essentially start with our original parent a four member chain. We are breaking the double bond because that's addition. So there will be no double bonnet anymore. We are adding a hydrogen atom a disposition but there's no need to show it because it's implicit. And at position number one we're adding B. H two. That's our first product that we get for reaction number one. Well done. Let's move on to reaction number two. Reaction number two states that were taking the product from part one. This is our product. So let's rejoin it. That's our product from the first part and the conditions we are using here. They are hydrogen peroxide in hydroxide, recall that whenever you're seeing these conditions and if you actually look at the whole context, we're using boring in tetra hydro Furin followed by hydrogen peroxide and hydroxide. Such a reaction is called hydro operation oxidation. You may also state that the first step was hydro operation because we added a molecule of boring and number two will be the oxidation step in the oxidation step. If you remember, we are essentially replacing beach to with our age. It's a multiple step mechanism which is a bit complex. We're D protein. Ating peroxide peroxide attacks born we have l kill shifts. Finally we have a nuclear attack and the deportation steps. So you don't have to worry about the step by step understanding of this reaction. You essentially want to keep in mind that the beach to group is now replaced with O. H. So that's what we're going to do. We're going to draw our structure with beach to being replaced by old age forming that alcohol which is the anti narcotic of alcohol since hydrogen was added to a more substituted position and wage group was added to a less substituted position and therefore we have our products. We may label them for complete clarity. These to our our our products and as a result we can see that the correct answer to this multiple choice question is B. However, if you still have any questions, feel free to leave them down below in the comments section and thank you for watching this video.

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1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

10. Addition Reactions

Hydroboration

Organic Chemistry

10. Addition Reactions

Hydroboration

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6:23 minutes

Problem 10a,b

Textbook Question

Predict the major products of the following reactions.
a. propene + BH₃⋅THF
b. the product from part (a) + H₂O₂/OH⁻

Verified step by step guidance

Step 1: Understand the reaction in part (a). Propene reacts with BH3 in the presence of THF (tetrahydrofuran) in a hydroboration reaction. This reaction follows anti-Markovnikov addition, where the boron atom attaches to the less substituted carbon of the double bond in propene.

Step 2: Recognize the stereochemistry of the hydroboration reaction. The addition of BH3 occurs in a syn fashion, meaning both the boron and hydrogen add to the same side of the double bond.

Step 3: Analyze the product of part (a). The product will be an organoborane intermediate, where the boron atom is bonded to the less substituted carbon of the original double bond in propene.

Step 4: Understand the reaction in part (b). The organoborane intermediate from part (a) reacts with H2O2 and OH− in an oxidation reaction. This converts the boron atom into a hydroxyl group (-OH), resulting in an alcohol.

Step 5: Predict the major product of part (b). The hydroxyl group will attach to the less substituted carbon of the original double bond in propene, following anti-Markovnikov addition. The stereochemistry of the product will retain the syn addition from part (a).

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Hydroboration-Oxidation

Hydroboration-oxidation is a two-step reaction process used to convert alkenes into alcohols. In the first step, an alkene reacts with borane (BH3) in tetrahydrofuran (THF) to form an organoborane intermediate. This step is characterized by syn-addition, leading to the formation of a trialkylborane. The second step involves oxidation with hydrogen peroxide (H2O2) and hydroxide ions (OH−), resulting in the formation of an alcohol.

Regioselectivity

Regioselectivity refers to the preference of a chemical reaction to yield one structural isomer over others when multiple possibilities exist. In the hydroboration step, the boron atom adds to the less substituted carbon of the alkene, following Markovnikov's rule. This results in the formation of a more stable, primary alcohol after oxidation, demonstrating the regioselective nature of the reaction.

Stereochemistry

Stereochemistry is the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. In the hydroboration-oxidation process, the addition of boron and subsequent oxidation occurs in a syn fashion, meaning that both the boron and the hydroxyl group will end up on the same side of the molecule. This stereochemical outcome is important for predicting the configuration of the final alcohol product.

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