A common and versatile synthetic route to (-) and (+) pentenomycin I, (+) halopentenomycin I and dehydropentenomycin

Asymmetric total synthesis of humulane sesquiterpenoids alashanoids B, C, E, and F and 2,9-humuladien-6-ol-8-one

Naturally occurring sesquiterpenes having humulane frameworks are structurally intriguing and possess significant biological profiles. Asymmetric synthesis of the alashanoids B, C, E, and F and 2,9-humuladien-6-ol-8-one is achieved for the first time through a linear synthetic strategy. Intramolecular late-stage Nozaki-Hiyama-Kishi (NHK) coupling is employed to access the eleven-membered macrocyclic core present in the target molecules. The NHK precursors are accessed using the Evans and non-Evans syn and anti-aldol reaction as a key transformation. X-ray and ECD analysis reconfirmed the synthesized compounds' structures and chirotopical properties.

Asymmetric Construction of the Core of C6, C7-Epoxy Daphnane Diterpenoid Orthoesters

Asymmetric construction of the core of C6, C7-epoxy daphnane diterpenoid orthoesters is developed through a convergent synthetic strategy. The salient features include a diastereoselective nucleophilic assembly of two bulky cyclic fragments, an oxidative cleavage/transesterification/aldol cascade to fashion the seven-membered ring, and a base-mediated transesterification/retro-aldol/aldol/epoxidation cascade to install the epoxy moiety with proper stereochemistry.