Protecting groups (intro)
Advanced Organic (UG) · Chemistry
Study notes
Reduce an ester in a molecule that also has a ketone. How? Step 1: Problem: reducing agent attacks both C=O groups. Step 2: Protect ketone as acetal: R₂C=O + HOCH₂CH₂OH (acid) → cyclic acetal. Step 3: Reduce ester (LiAlH₄) — acetal survives. Step 4: Deprotect: aqueous acid → ketone back. Protect–react–deprotect!