Page 548 - Applied Pharmacognosy

4. Claisen reactions: 547

• S-ester is more active Malonyl-CoA
than o-esters

• malonyl-CoA is more
reactive than acetyl-CoA.

• Because, the α-hydrogens
are flanked by two C=O
groups, and have
increased acidity, thus a
more favorable to
nucleophile.