Question

CH3-COOH-CH-COO-

3-hydroxybutyrate or β-hydroxybutyrate

I have no idea why this is named what it is named.
I know that the COO on the end is the most oxidized. I don't understand why a 3 is being used. Would it not be 4 b/c there are 4 carbons. I'm just overall confused with how this is named.

Answer 1

I think you made a typo when you typd the question. I think what you meant to type is
CH3-CHOH-CH2-COO^- and is shown at this link.
http://en.wikipedia.org/wiki/Beta-Hydroxybutyric_acid

Start counting with the functional group, COOH in this case). C of COOH is carbon 1, the CH2 to the left is C2 and the C of CHOH is 3; therefore, this is 3-hydroxy etc. Yes there are four carbons; however, the OH is attached to C3 and not to C4.The 3 is to tell you that the OH is on C3 and not some other C.

Answer 2

Where is the butyrate coming form. I now understand the 3-hydroxy aspect of it but how is the end named? Thanks Dr.Bob