Annulation

Definition

Annulation in the context of organic chemistry, particularly within the realm of carbonyl condensation reactions, refers to the process of forming ring structures by reacting two molecules to create a new cyclic molecule. It is a critical step in synthesizing complex organic compounds, including natural products and pharmaceuticals.

Related terms

Carbonyl Condensation Reaction: A reaction where two carbonyl-containing molecules combine, typically involving an aldehyde or ketone, leading to the formation of a larger molecule.

Robinson Annulation Reaction: A specific chemical reaction that combines elements of Michael addition and aldol condensation to construct complex ring systems found in many natural products.

Cyclization: The process of forming a cyclic structure from linear precursors, often involving making single or multiple rings within an organic molecule