Two approaches to the synthesis of an oxabicyclic pyrrolidine-6one are described using enzymatic resolution and goldmediated catalysis as key steps toward enantiopure compounds previously reported as racemic mixtures. Addition of Grignard reagents to the ketone afforded a variety of diversified tertiary alcohols of interest for their reported pharmacological activities.
For the first time, we describe the
stereocontrolled total syntheses
of olivil, cephafortin A, 4-des-O-methyl-4-O-rhamnosyl cephafortin A, and alashinol F from a common
precursor using a combination of chemoenzymatic and biomimetic methods
for the systematic introduction of functional groups on three vicinal
stereogenic carbon atoms. We revised the previously assigned stereochemistry
of (+)-cephafortin A, which was reported as the enantiomer. Natural
and unnatural congeners provide insights into the biogenetic interrelations
of members of this family.
This communication describes the stereoselective synthesis of C1-C16 fragment of antascomicin A, a non-immunosuppressive immunophil-binding natural product. Evans aldol reaction was used extensively to install all the stereo centres present in the fragment. The hemikatel present in the fragment was synthesized via DMP-mediated oxidation of β-hydroxy amide followed by acid catalyzed hemiketalization.
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.