berkeley review orgo example 2.15

[fastfingers]

it says that pentanal can be distinguished with a 1H triplet at 9.7 ppm. Shouldn't this be a singlet since the neighboring Carbon has no hydrogens?

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[TwoPaddles]

it says that pentanal can be distinguished with a 1H triplet at 9.7 ppm. Shouldn't this be a singlet since the neighboring Carbon has no hydrogens?

yes it should be a singlet, it's probably a typo

 

[gmcguitar4]

The carbon adjacent to the carbonyl carbon has 2 protons next to it doesn't it? So the NMR detects the aldehyde proton downfield at 9.7, but splits the signal into a triplet due to those 2 protons.

 

[shffl]

I thought it was an error too until I realized I got tricked. The neighboring carbon has two hydrogens. Initially I thought the neighboring carbon is that of the carbonyl but it actually isn't. We just thought it is due to the way we imagine how an aldehyde looks like. We see C-c-H and we thought to ourselves c is the neighboring carbon but it's actually the other one.

 

[BerkReviewTeach]

i thought it was an error too until i realized i got tricked. The neighboring carbon has two hydrogens. Initially i thought the neighboring carbon is that of the carbonyl but it actually isn't. We just thought it is due to the way we imagine how an aldehyde looks like. We see c-c-h and we thought to ourselves c is the neighboring carbon but it's actually the other one.

Exactly!

H-C(=O)-CH2-CH2CH2CH3