Carbonyl Condensation Reactions in Synthesis The Robinson Annulation Reaction

Carbonyl Condensation Reactions in Synthesis The Robinson Annulation Reaction... 

Carbonyl condensation reactions are perhaps the most versatile methods available for synthesizing complex molecules. By putting a few fundamental reactions together in the proper sequence, some remarkably useful transformations can be carried out. One such example is the Robinson annulation reaction for tire synthesis of polycyclic molecules. The word annulation comes from the Latin annulus, meaning "ring," so an annulation reaction builds a new ring onto a molecule. 

Carbonyl condensation reactions are widely used in synthesis. One example of their versatility is the Robinson annulation reaction, which leads to the formation of substituted cyclohexanones. Treatment of a i dikotone or -keto ester u-itb an o,fi-unsaturated ketone leads first tu a Mie nael addition, which is followed by intramolecular aldol cycUaatinn. Condensation reactions are also used widely in nature for the bionyntbesis of such molecules as fats and steroids. 

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