Organic Chemistry draw electron flow arrows for acid-base reaction!?

Question

Hello i've researched this question and tried it numerous times but i keep getting it wrong for some reason....any help would be greatly appreciated

the question is Draw the electron-flow arrows that lead from starting materials to products in this acid–base reaction.

here is the image of the reaction taking place

http://i45.photobucket.com/albums/f57/yaoixlover/Untitled.jpg

Answer 1

I suggest you go to this website: http://orgo.curvedarrow.com/punbb/viewforum.php?id=2

There are several acid-base examples posted there, though not with your example.



Let me digress on curved arrows. Curved arrows always start with a pair of electrons. In the examples, you will see a simple modification of pushing electrons. The traditional curved arrows are ambiguous if the curved arrow starts with a pair of electrons shared by two atoms. This ambiguity is avoided by using a “pre-bond” or dashed line to indicate which atoms will be joined. When used with a curved arrow, it shows which electrons move to make or break bonds and makes pushing electrons consistent and unequivocal in meaning.



I believe you should be able to examine your example and if you follow the examples with pre-bonds, you can see that a new bond forms between the nitrogen and oxygen. Since the nitrogen becomes positively charged and you do not see the non-bonded electrons in the product, it is the electrons on the nitrogen that form the N-H bond. Similarly, the H-O bond becomes cleaved and those electrons end up on the oxygen atom.



If you need help contact me at www.curvedarrowpress.com.



The examples on the forum are either from "A Guide to Organic Chemistry Mechanisms©" http://www.curvedarrowpress.com or written in the same manner. Chapter 2 has many examples of pushing electrons for acid-base reactions, drawing curved arrows, and predicting their equilibrium. Also, you will see the problems are written at three levels so you would be able to master this topic at the easiest level and then progress to a more advanced level.

Answer 2

Electron Flow In Organic Chemistry

Answer 3

If NH2 already has a -1 charge it isn't going to lose another proton any time soon. A -1 charge is unstable enough, just imagine a -2 charge. What I believe is most likely to happen is that the negative charge of the NH2 will most likely attack the pi bond of the terminal carbon and create a carbanion H2N-C-C(-)-CH3 The carbanion could then easily snag a hydrogen from a free floating ammonia NH3 or water if there is any since the reaction would have to be under basic conditions (because of the negative charge). This may not be correct just a warning. It's just what I think is more likely.

Answer 4

There shud actually be two arrows.

1 moving from the lone pair of electrons in N: towards the H bonded to O

and the other moving from the H-O bond towards the same O.

Answer 5

The arrow should be from the lone pair of N from N(CH3)3 to the acidic H of acetate, removing it from acetic acid and leaving the electron to the O of acetic acid. So in the end you get HN+(CH3)3 and acetate ion.