An unprecedented C-C coupling reaction between alkenes and ketones by hydrogen-atom transfer, using Fe(acac) and PhSiH in EtOH, is described. This mild protocol features high site selectivity and allows the construction of sterically congested structures containing tertiary alcohols and quaternary centers. The overall process introduces a novel strategic bond disconnection for ring-closing reactions.

A diastereoselective synthesis of cis-5-oxodecahydroquinolines is described in which three stereocenters are generated in a one-pot reaction. The reaction involves a lithium hydroxide-promoted Robinson annulation/intramolecular aza-Michael domino process from an achiral acyclic tosylamine-tethered β-keto ester. The development and scope of this reaction was facilitated through the use of DFT-based mechanistic studies, which enabled the observed diastereodivergent course of the azacyclization to be rationalized. The varying stereochemistry and stability of the resulting decahydroquinolines was found to depend on whether a β-keto ester or ketone were embedded in the substrates undergoing aminocyclization. This synthetic approach gave access not only to both diastereomeric cis-decahydroquinolines from the same precursor, but also to the corresponding trans isomers, through an epimerization processes of the corresponding N-unsubstituted cis-5-oxodecahydroquinolines. The described methodology provides advanced building-blocks with the three relative stereochemistries required for the total synthesis of phlegmarine alkaloids.

A revised structure for the Lycopodium alkaloid huperzine N is proposed and confirmed by synthesis. The key synthetic steps involve an epimerization of a cis-5-oxodecahydroquinoline to the corresponding trans isomer and a coupling, followed by a diastereoselective hydrogenation using Wilkinson's catalyst to incorporate the pyridylmethyl moiety. This route allowed the alkaloid serralongamine A to be synthesized for the first time, and two additional steps led to the revised structure of huperzine N, both products bearing an unusual decahydroquinoline stereostructure.

An unprecedented C À Cc oupling reaction between alkenes and ketones by hydrogen-atom transfer,u sing Fe-(acac) 3 and PhSiH 3 in EtOH, is described. This mild protocol features high site selectivity and allows the construction of sterically congested structures containing tertiary alcohols and quaternary centers.T he overall process introduces an ovel strategic bond disconnection for ring-closing reactions.

A straightforward synthetic entry to functionalized hydrindane compounds based on a rapid assembly of the core nucleus by a Danheiser cycloaddition is reported. Valuable bicyclic building blocks containing the fused five and six-membered carbocyclic ring system can be achieved in only four steps from a simple acyclic β-keto ester.

Synthetic and DFT Studies Towards a Unified Approach to Phlegmarine Alkaloids: Aza-Michael Intramolecular Processes Leading to 5-Oxodecahydroquinolines. -(BRADSHAW*, B.; LUQUE-CORREDERA, C.; SABORIT, G.; CATIVIELA, C.; DOREL, R.; BO, C.; BONJOCH, J.; Chem. -Eur.

Phlegmarine alkaloid serralongamine A (I) is prepared for the first time and transformed into huperzine N (II) allowing for a revision of it′s putative structure.