“…Some important chemical components including diterpenoids, sesquiterpenoids, and bisflavones have been isolated from the leaves, bark, and wood of this plant . Among them, taiwaniadducts, including various novel dimeric diterpenoids (DDs) and a cycloaddition product of a monoterpene and a diterpenoid, have attracted much attention from organic chemists due to their complex structures and varied linkage types. − To data, no less than 180 DDs have been obtained from natural sources, and nine taiwaniadducts have been isolated from T. cryptomerioides . , These taiwaniadducts are connected with a labdane unit and an abietane unit with characteristic [2 + 2], [4 + 2] (Diels–Alder, DA), and [5 + 2] cycloaddition linkage types. − The DA cycloadducts are synthesized via regular cycloaddition reactions between the conjugated Δ 12(13),14(15) double bonds of the isoprene unit in the labdane moiety and the Δ 7(8) electron-deficient double bond in the abietane unit to generate a six-membered ring. , In a search for structurally diverse DDs and potent bioactive components, a pair of unique C 37 heterodimeric diterpenoid stereoisomers, taicrynacids A ( 1 ) and B ( 2 ), have been obtained from the leaves of T. cryptomerioides . These possess an uncommon decalino[1,2,3- de ]benzopyran heterotetracyclic core formed by a hetero [4 + 2] (Hetero-Diels–Alder, HDA) cycloaddition. , The HDA cycloaddition reaction generates a pyranoid D-ring via the α,β-unsaturated carbonyl group in the podocarpane (trinorabietane) unit (diene) and the double bond of the labdane unit to form the unique heterotetracyclic core.…”