Transesterification refers to exchanging the alkoxy group of an ester with which substance?

Master NCEA Level 3 Organic Chemistry Reaction Schemes. Prepare with multiple choice questions, complete with hints and detailed explanations. Ace your exam with our comprehensive tools!

Transesterification is the process where the alkoxy group on an ester is swapped for the alkoxy group of another alcohol. The incoming alcohol acts as a nucleophile and attacks the carbonyl carbon of the ester, usually with an acid or base catalyst. A tetrahedral intermediate forms, and the original alkoxy group leaves as an alcohol, yielding a new ester and the first alcohol. Water would instead hydrolyze the ester to a carboxylic acid and an alcohol, not swap the alkoxy group. The catalyst (acid or base) facilitates the reaction but is not the exchanging partner. So the substance that exchanges the alkoxy group is another alcohol.