Number of primary carbons?

[yankswin2011]

How many primary carbons are in ethyl acetate? By definition, a primary carbon is one that is singly bonded to only one other carbon.

I think it is 4 primary carbons but others think it is 2 because you do not count the "primary carbons" in the functional group.

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[DrJMR]

Primary carbons are carbons that are connected (covalently) to only one other carbon. I agree with you, I see four. 👍

Out of curiosity, what is the source of this question?

 

[yankswin2011]

Thanks!
My question is simplified version of the TBR, OC1, p. 295 (Passage V), question 33. With respect to the Oriental Fruit Moth Sex Attractant, E-8-Dodecen-1-yl acetate, TBR's answer appears to suggest that this molecule only has 2 primary carbons, which is wrong for the reason you articulated.

To be honest, I have come across several TBR answers that are wrong due to carelessness in drafting (i.e. TBR, OC1, p. 289, Question 5).

 

[DrJMR]

However, I do see their argument (which would be EXTREMELY nit-picky):

The carbon attatched to the carbonyl group is not ONLY attatched to one other carbon, it is attatched to the carbonyl group and the ester oxygen.

Likewise, the penultimate carbon on the right is connected not ONLY to the carbon at the end, but the ester oxygen as well.

Regardless, I'm pretty sure AAMC will not ask such a "Kaplan-like," overspecific question!

 

[yankswin2011]

However, I do see their argument (which would be EXTREMELY nit-picky):

The carbon attatched to the carbonyl group is not ONLY attatched to one other carbon, it is attatched to the carbonyl group and the ester oxygen.

Likewise, the penultimate carbon on the right is connected not ONLY to the carbon at the end, but the ester oxygen as well.

Regardless, I'm pretty sure AAMC will not ask such a "Kaplan-like," overspecific question!

Indeed, if by definition, a primary carbon is a carbon that is attached to only 1 carbon, and nothing else, then yeah, very tricky. However, I guess I'm not worried about how TBR interprets what a "primary carbon" means but what the AAMC interprets what a "primary carbon" means. So, then, you agree that methyl acetate has only 2 primary carbons, right?

 

[DrJMR]

Yup, I'll go against my will and agree with TBR 👎