Claisen condensation symmetry

Upon Claisen condensation of two molecules of malonyl CoA with one another, a molecule of acetonedicarboxylic acid CoA ester would be formed which could either be hydrolyzed to the free acid or further activated to its bisCoA thioester. It is important that the derivative (30) have C2V symmetry to explain the labehng pattern in (27). The monoCoA ester would not fulfil this condition After condensation of (30) with (14), the keto acid (29) would be obtained and would show two distinct labeling patterns depending on which of the methylene... 

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