Home > Community > Conversion of methylcyclopentanol to cyclopentanone
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+ Elimination
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Khurram Shezad

Conversion of methylcyclopentanol to cyclopentanone

Christopher Jenkins  Follow

If you leave it to E1, you will not get the selectivity you need.

The difference between the methyl group and the methylene unit is steric bulk. You can select for deprotonation of the methyl for elimination via a bulkier base in an E2 reaction.

In addition, you will need to convert the substrate so that it has a good leaving group. For an alcohol, this is typically accomplished by first converting to a tosylate or a mesylate.

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Edward Elric  Follow
Ah OK. Still good to know though. Thanks for the feedback. @user55119More
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Jean Hildesheim  Follow
From my own experience. Used to put reaction in a freezer to form tosylate and avoid formation of chloride in more complex tertiary alcohols. It doesnt matter much in this case if it is a mixture of tosylate and chloride.More
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Harvey Wachtel  Follow
@user55119 I strongly doubt that that tosylate will react as is without heating (Please provide a reference if you have reason to believe my intuition is wrong. It might be.). Sn1 reactions can be messy, and I have a strong preference not doing that when possible.More
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Eric Bernier  Follow
Thank u so much... So that means I will have to treat it first with TsCl and then with tertiary butoxide (a bulky base) to get the Hoffman product and carry out the further reaction.More
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Eugene Buff  Follow
If you are dealing with 1-methylcyclopentanol, this reactive tosylate may form the chloride in situ. Why not treat the alcohol with HCl to form the chloride initially and then proceed?More
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