Robinson’s approach

Later, Robinson s approach was improved substantially by Schopf in the early 1930s when he realized that only slight changes of the pH affect the yield of the reaction. After in-depth studies concerning the optimal reaction conditions, buffered conditions using a citrate buffer (pH=5) where found to double the initial yield of the reaction [133]. Therefore, the synthesis of tropinone from sncci-ndialdehyde, Af-methylamine, and acetonedicarboxylate is nowadays commonly referred to as Robinson-Schopf condensation. 

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