Recent advances in the total synthesis of limonoid natural products: a decade of progress

Limonoid natural products are highly oxygenated tetranortriterpenoids with broad-spectrum biological activities, yet their compact polycyclic frameworks and multiple contiguous stereocentres render them formidable targets for total synthesis. This review summarizes recent advances in the total synthesis of limonoid natural products from 2017 to 2026. The discussion is organised by the structural classification of limonoids, covering ring-intact limonoids, ring-seco limonoids (including ring C-seco, D-seco, A,D-seco, and B,D-seco types), rearranged limonoids, and limonoid alkaloids. Emphasis is placed on key strategic disconnections and the emergence of modern methodologies such as photoredox catalysis, C-H activation, metal-hydrogen-atom-transfer-mediated radical cyclisation, and chemoenzymatic approaches.