Organocatalytic Asymmetric Cyclization Reactions with <i>γ</i>‐Hydroxyenones

This review article provides an overview of the recent developments in organocatalytic asymmetric cyclization strategies utilizing γ ‐hydroxyenones. Due to the bifunctional nature of γ ‐hydroxyenones, it is a powerful building block for synthesizing oxygen‐ and nitrogen‐containing heterocycles. The cyclization strategies are systematically categorized based on the nature of the organocatalysts employed: (i) chiral prolinol analogs, which obtain tetrahydrofuran‐fused 3,4‐dihydrocoumarins and 2,3,4‐trisubstituted tetrahydrofurans; (ii) chiral bifunctional squaramides, affording diverse spirocyclic frameworks such as spiro‐tetrahydrofuran‐pyrazolones, morpholinones, and oxindole‐derived systems; (iii) chiral bifunctional thioureas, which forms 1,3‐dioxolanes, oxazolidines, and cyclic acetals; (iv) multifunctional modular organocatalysts, affording enantioenriched α , β ‐disubstituted γ ‐butyrolactones; and (v) other chiral organocatalysts which cannot be grouped in previous categories such as Song's chiral oligoethylene glycol as a cation‐binding catalyst leads to the generation of chiral 1,4,2‐dioxazinanes.