A new TiIII‐mediated reductive epoxide‐opening/ Beckwith–Dowd rearrangement process efficiently assembles the bicyclo[3.2.1]octane framework of highly oxidized grayanane diterpenoids. By incorporation of a Cu(tbs)2‐catalyzed (tbs=N‐tert‐butylsalicylaldiminato) intramolecular cyclopropanation, a diastereoselective oxidative dearomatization‐induced Diels–Alder cycloaddition and a MeReO3‐catalyzed Rubottom oxidation, this approach has enabled the first total syntheses of rhodomolleins XX and XXII in 23 and 22 steps, respectively.
The first asymmetric total synthesis of (+)-jatrophalactam was reported, which unambiguously determined the absolute configuration of the titled natural product. The key features entail a conformationally controlled cyclopropanation, a Meldrum's acid adduct-engaged macrolactam formation, and a Pd(II)-mediated oxidative cyclization.
The first and asymmetric total syntheses
of two C11-oxygenated
hetisine-type diterpenoid alkaloids, namely, (+)-davisinol and (+)-18-benzoyldavisinol,
is described. The concise synthetic approach features a HAT-initiated
transannular redox radical cyclization, an ODI-Diels–Alder
cycloaddition, and an acylative kinetic resolution. By incorporating
an efficient late-stage assembly of the azabicycle, our strategy would
streamline the synthetic design of C20-diterpenoid alkaloids
and pave the way for their modular syntheses.
The first enantioselective total synthesis of (+)-alsmaphorazine E has been achieved through a traceless chirality transfer strategy, which also enabled structural reassignment of the natural product. Key features of this efficient approach entail a catalytic intramolecular oxidative cyclization, a diastereoselective oxidative cyclic aminal formation and a radical cyclization/transannular aza-Michael addition cascade.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.