[FailedPreMedStudent]

I am going through practice problems to figure out if a reaction will undergo SN2 or SN1 but I am stuck on one of the reactions.



According to the book "there is no leaving group" which I assume means their is no good LG, and thus neither SN2 or SN1 occur.

Why is -OCH3 not a good leaving group?

I know that good LGs are weak bases, so how do I know whether a base is weak or strong?

[rolnor]

Here is a link;

http://www.uwindsor.ca/people/jgreen/sites/uwindsor.ca.people.jgreen/files/pka_bases.pdf

[hollytara]

This is a fundamental thing you need to understand - go back and read your textbook!

Or get one of the co-teaching aids like "Maximum Success, Minimum Effort" by Fredlos or "Organic as a 2nd Language" by Klein

[Meter]

My organic chemistry is a bit rusty, so forgive me if this is wrong, but in acid-base chemistry we can predict the strength of an acid or base by evaluating the stability of its conjugate. A stable conjugate acid/base predicts a strong acid/base and likewise an unstable conjugate will predict a strong acid/base.

Please correct me if I'm wrong.

[Babcock_Hall]

One has to find the pK_a of the conjugate acid of the leaving group.  Students sometimes get hung up on this part of the process.