how to know which is alpha or beta carbon in this structure ?

[dentalstudent2021]

Hey guys. I understand that the alpha is first carbon from carbonyl group. but i don't understand when there are 2 carbonyls which is alpha (and then beta) .

picture attached of sample structure.

Thanks!

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[DAT Destroyer]

Hey guys. I understand that the alpha is first carbon from carbonyl group. but i don't understand when there are 2 carbonyls which is alpha (and then beta) .

picture attached of sample structure.

Thanks!

This is a good question.
You are correct about alpha carbons. If there are 2 carbonyls, there may be more than one alpha carbons and may be more than one alpha hydrogen.

In your example they are talking about Alpha and beta carbonyls.
So, if for example you have a carboxylic acid, or an Ester, this carbonyl is the primary point of orientation. Then you will see another carbonyl, beta to the acid or ester carbonyl. That is why they are saying, it is a beta KETO-ester or Beta KETO-acid. The carbonyl carbons are beta to each other.

Hope this helps.