Textbook Question
Predict the product for the acid-catalyzed pinacol rearrangement of the following diols.
(b)
21. Aldehydes and Ketones: Nucleophilic Addition
Ketone and Aldehyde Synthesis Reactions
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Provide the major product for the following reaction.
A
B
C
Verified step by step guidance1
Identify the type of reaction: The reaction involves the addition of BH3 in THF followed by oxidation with H2O2 and OH-. This is a hydroboration-oxidation reaction, which is used to convert alkynes to aldehydes or ketones.
Determine the regioselectivity: Hydroboration-oxidation of terminal alkynes typically results in the formation of an aldehyde. The boron adds to the less substituted carbon of the alkyne, leading to anti-Markovnikov addition.
Analyze the structure of the starting material: The starting material is a cyclohexyl alkyne. The alkyne is terminal, meaning the triple bond is at the end of the carbon chain.
Predict the intermediate: The initial hydroboration step will add BH2 to the terminal carbon of the alkyne, forming a vinyl borane intermediate.
Determine the final product: The oxidation step replaces the B-H bond with an O-H bond, resulting in the formation of an aldehyde. Therefore, the major product will be a cyclohexyl aldehyde.
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Ketone and Aldehyde Synthesis Reactions practice set
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