Fig. 2: The latent synthon strategy for asymmetric Diels–Alder reaction, a straightforward and unifying synthesis of chiral norbornanes and norbornenes.

a Chiral norbornanes (NBAs)/norbornenes (NBEs). b Synthesis of NBEs via Diels–Alder reaction. c Diels–Alder synthesis of NBEs using the latent synthon strategy. d Facile synthesis of the key alkene latent synthon, ON-alkene. THF, tetrahydrofuran; aq., aqueous solution; NHPI, N-hydroxyphthalimide; DIC, N,N’-diisopropylcarbodiimide; DMAP, 4-dimethylaminopyridine.