The stereoselective syntheses of synargentolide B and its three stereoisomers have been accomplished from L‐(+)‐ and D‐(–)‐diethyl tartrates, D‐ribose, and D‐mannitol as chiral pool starting materials. The key step was a tandem ring‐closing/cross‐metathesis reaction in which lactone formation and fragment coupling were accomplished in one pot. The spectroscopic data of synthetic product 2c were in agreement with those reported for the natural product. Synargentolide B isolated by Rivett et al. and the compound isolated by Pereda‐Miranda et al. are not diastereomers, but rather they are identical.
An efficient synthesis of the C1-C19 segment of carolacton is described, starting from D-ribose, (-)-β-citronellene and a homopropargylic alcohol, and which employs a Nozaki-HiyamaKishi (NHK) coupling as the key step. Other important steps are cross-metathesis and Evans aldol reactions.
New polycyclic hexahydrobenzo[c]acridines were synthesized in excellent yields by intramolecular [4+2]-cycloaddition reactions of aldimines derived from aromatic amines and 2-(4-methylpent-3-en-1-yl)benzaldehyde in acetonitrile in the presence of 10 mol% of bismuth(III) chloride. The reaction is highly diastereoselective, giving cisfused benzoacridine derivatives preferentially.
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.