SN2 reaction of carboxylate ions with alkyl halides to give esters
Description: Alkyl halides (or tosylates) will react with carboxylate ions to form esters. This is an SN2 reaction. [private_ReactionGuide]
Notes: X here is a halide (Cl, Br, I) or sulfonate (OTs, OMs)
The counter-ion on the carboxylate can be any alkali ion, such as Li, Na (pictured) or K.
Notes: Note that since this is an SN2 reaction and proceeds via backside attack, there will be inversion of configuation at the carbon (note the last two examples).
Mechanism: In the SN2 reaction the nucleophile (RCOO-) attacks the carbon with the good leaving group, forming a C–O bond and breaking the C–Br bond (Step 1, arrows A and B).