Because they are so often used as protecting groups in organic synthesis, the choice of which acetal to form metimes hinges upon how easily it can be removed by hydrolysis. This is because the longer it takes to protect and the harsher the necessary conditions, the more likely it is that unwanted side reactions will occur. eally an acetal protecting group should be easily formed and easily removed. For this reason, methylene etals like the one shown below are not ideal, as their rates of hydrolysis are quite slow. Acetonides, which u encountered in the practice problems, are often better choices. Fill in the boxes below with the expected drolysis products in each case. Then, using your knowledge from part (b) and clearly-drawn resonance uctures, briefly explain this observed difference in rates of hydrolysis. H30* H3C `CH3 (relatively slow) methylene acetal Hydrolysis Products H3C CH3 H3O* (relatively fast) H3C° CH3 acetonide Hydrolysis Products

Because they are so often used as protecting groups in organic synthesis, the choice of which acetal to form metimes hinges upon how easily it can be removed by hydrolysis. This is because the longer it takes to protect and the harsher the necessary conditions, the more likely it is that unwanted side reactions will occur. eally an acetal protecting group should be easily formed and easily removed. For this reason, methylene etals like the one shown below are not ideal, as their rates of hydrolysis are quite slow. Acetonides, which u encountered in the practice problems, are often better choices. Fill in the boxes below with the expected drolysis products in each case. Then, using your knowledge from part (b) and clearly-drawn resonance uctures, briefly explain this observed difference in rates of hydrolysis. H30* H3C `CH3 (relatively slow) methylene acetal Hydrolysis Products H3C CH3 H3O* (relatively fast) H3C° CH3 acetonide Hydrolysis Products

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter11: Ethers, Epoxides, And Sulfides

Section: Chapter Questions

Problem 11.18P

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