Cyclic hemiacetals commonly form if a molecule has both an alcohol group and a carbonyl group elsewhere in the same molecule, especially if they are four or five carbons apart. What is the structure of the hydroxy aldehyde from which this hemiacetal might form?

Question

Cyclic hemiacetals commonly form if a molecule has both an alcohol group and a carbonyl group elsewhere in the same molecule, especially if they are four or five carbons apart. What is the structure of the hydroxy aldehyde from which this hemiacetal might form?

Accepted Answer

All right. Hi, everyone. So this question says that a cyclic hemi aal can be formed when an alcohol group and a Carboni group are present in the same molecule. Specifically, if the two groups are four or five carbons away or the cyclic chem acetyl, shown below predict the structure of the hydroxyl aldehyde. It was formed from. So first and foremost, like the question implies here, a hemi acetyl is a product formed between an aldehyde and an alcohol. An aldehyde is a functional group in which we have a car bal or a carbon atom double bonded to oxygen. Now, the aldehyde has at least one hydrogen atom attached to the carbon carbon and one R group or a carbon chain. So when the aldehyde reacts with an alcohol, you get the hemi AOP, the car bottle oxygen in the heal is converted into a hydroxy group or an oh group. Now, the alcoy group of the alcohol is going to also attach itself to the car bono carbon and we still have hydrogen from the original aldehyde. So in this case, we do have a cyclic hemi AOP. So in this case, we have a hydroxy group. So in the context of a cyclic hea the carbon atom connecting to the hydroxy group was originally the car bono carbon. This means that the oxygen atom inside of the ring was part of the alcohol group. So because the aldehyde and alcohol functional groups were present in the same molecule, the molecule itself for lack of a better phrase folded in on itself, we created a ring structure. So to understand what the hydroxy aldehyde looks like. I'm going to break the bond between the car bono carbon and the oxygen inside of the rink. Now recall that in the case of aldehydes, the carbonel is going to be at the very end of the carbon chain in which the aldehyde carbon or the car bono carbon is number one. So I'm going to go ahead and number my carbon atoms from the carbon carbon all the way up to the carbon atom connecting to the oxygen of the ring. So that's six and I have an additional ethel group which can extend my parent chain. So in this case, I have an eight carbon parent chain with an aldehyde functional group at the very end. So at the end here goes make Caronne. So according to my numbering pattern here, I have an additional ethel group attached to carbon three and the hydroxy group on carbon six. So after I fixed the EO group on carbon three, I'm going to go ahead and attach the hydroxy group on carbon six and there you have it. So the hydroxy aldehyde that formed the cyclic he acetyl that we can see on screen was three ethel six hydroxy tanna and there you have it. So with that being said, thank you so very much for watching and I hope you found this helpful.

Cyclic hemiacetals commonly form if a molecule has both an alcohol group and a carbonyl group elsewhere in the same molecule, especially if they are four or five carbons apart. What is the structure of the hydroxy aldehyde from which this hemiacetal might form?

Verified video answer for a similar problem:

Key Concepts

Cyclic Hemiacetals

Carbonyl Group

Hydroxy Aldehyde