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A synthesis of the tricyclic partly substituted core structure of palhinine A was achieved. To reach the bicyclo[2.2.2]octane motif a domino Michael reaction was employed as a key step. After Arndt-Eistert homologation and intramolecular aldol reaction the isotwistane core could be obtained after simple functional-group manipulations. [ABSTRACT FROM AUTHOR]

An effective synthesis of the tricyclic core structure of the new diterpene crotogoudin was achieved. The synthesis features an intermolecular domino Michael reaction to construct a bicyclo[ 2.2.2]octane motif and an aldol condensation to close ring B. Stork reductive alkylation with allyl bromide proceeded from the β side, resulting in the wrong stereochemistry at C-10. [ABSTRACT FROM AUTHOR]

Olefination of ester 26 which was obtained from acid 20 and alkenol 25 using a reduced titanium ethylidene reagent led to cyclic enol ether 28 which could be cyclized by iodospiroacetalization to the spiroacetal core of the antifungal compound spirofungin A (5). [ABSTRACT FROM AUTHOR]

The synthesis of three key fragments of the novel 16-membered macrolide leiodermatolide is described. The stereotetrad-containing building block was prepared via a Marshall-Tamaru reaction on an aldehyde obtained by organocatalysis. For a second building block, a Marshall-Tamaru reaction was used as well. The side-chain fragment containing a hydroxy δ-lactone could be obtained by intramolecular Reformatsky reaction. [ABSTRACT FROM AUTHOR]

It was discovered that substituted hex-5-yne-1,4-diols like 16, 28, and 30 undergo a domino sequence of Meyer-Schuster rearrangement followed by Michael addition forming 2,5-disubstituted tetrahydrofurans in presence of PtCl2. [ABSTRACT FROM AUTHOR]

An effective total synthesis of the trinorditerpenoid moluccanic acid methyl ester has been achieved. The synthesis features a Robinson annulation, followed by aromatization to construct the aromatic ring and Baeyer-Villiger oxidation of the A ring to finish the target molecule. [ABSTRACT FROM AUTHOR]

An advanced intermediate vinyl iodide corresponding to the C1-C13 fragment of the macrolide biselyngbyaside was prepared by a cross-metathesis reaction between vinyl alcohol and alkene building blocks. The latter fragment, containing two stereo-centers, was obtained by employing an asymmetric alkylation, a Wittig reaction, a hydrozirconation, and a Brown allylation as key steps. [ABSTRACT FROM AUTHOR]