Predict the major, organic product for the following reaction. <img src="https://media.pearsoncmg.com/ph/esm/ecs_mullins_organic1e/msa/content/practice-test/img/Ch10_Q11_QT.jpg" alt="The figure illustrates a reaction in which the product has to be determined. The reaction contains three reactants. The first reactant has the following structure: A 5-carbon pentagonal ring is in a vertical orientation with C 1 occupying the topmost vertex. C 2 is single bonded to C 1 of a 2-carbon alkyne chain depicted as a line structure using 3 parallel lines. C 5 is single bonded to C H 3 in the form of a line. The second reactant is B H 3 written over the reaction arrow. The third reactants are H 2 O 2 and N a O H written under the reaction arrow." />

Table of contents

Skip topic navigation

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

Alkyne Hydroboration

Organic Chemistry

10. Addition Reactions

Alkyne Hydroboration

Previous problemNext problem

Struggling with Organic Chemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

Predict the major, organic product for the following reaction.

The figure illustrates the structure of a molecule. A 5-carbon pentagonal ring is in a vertical orientation with C 1 occupying the topmost vertex. C 2 is single bonded to C 1 of a 2-carbon alkane chain depicted as a line structure using 1 line. C 2 of the alkane chain is single bonded to O H below and O H on the upper right. C 5 is single bonded to C H 3 in the form of a line.

Previous problemNext problem

Verified step by step guidance

Identify the reaction type: The reaction involves hydroboration-oxidation of an alkyne. This is a two-step process where the alkyne is first treated with borane (BH3) and then oxidized with hydrogen peroxide (H2O2) in the presence of sodium hydroxide (NaOH).

Understand the regioselectivity: Hydroboration-oxidation of alkynes typically leads to anti-Markovnikov addition, where the boron adds to the less substituted carbon of the alkyne, resulting in an enol that tautomerizes to a carbonyl compound.

Predict the intermediate: The initial addition of BH3 to the terminal alkyne will result in the formation of a vinyl borane intermediate. This intermediate will have the boron atom attached to the less substituted carbon of the alkyne.

Perform the oxidation step: The vinyl borane intermediate is then oxidized by H2O2 in the presence of NaOH, converting the boron group into a hydroxyl group. This results in the formation of an enol.

Consider tautomerization: The enol formed in the previous step will undergo tautomerization to form the more stable keto form, which is an aldehyde in this case. This is the major organic product of the reaction.