[Rutherford]

Got two quick questions:

1.To which carbon atom (indicate the serial number) will chlorine mainly add in the reaction of HCl with penten-2-oic acid?
A) 1, B) 2, C) 3, D) 4, E) 5.
Answer is C) but C) and B) are similar, but is it 3C) because of the induced effect (O is pulling the electrons)?

2.Which of these organic acids is the strongest?
A)benzoic, B) 2-chlorobenzoic, C) 4-methylbenzoic, D) 2-aminobenzoic, E)4-bromobenzoic.
Why B) and not D)?

[discodermolide]

In the pent-2-enoic acid The C3 is the most positively charged due to the oxygen atom of the acid carbonyl. If you protonate this you can draw a stabilised resonance form placing the positive charge on C3. This will then get attacked by Cl^-.

2- Amino benzoic acid is probably an internal zwitterion where you have NH3⁺ CO2^-. Therefore it is not an acidic molecule.

I can draw what I mean if you want?

[Rutherford]

Okay, thanks, I forgot that property of amino acids.