Its Possible Role in the Biosynthesis of Eudesmane Sesquiterpenes

During the synthesis of 14, a pronounced example of through-bond interactions (TBI) was observed.

Total Synthesis and Stereochemistry of 13-Hydroxy-α-eudesmol[J].

Both fragmentation reactions result in the regio- and stereospecific formation of two E double bonds as present in the ten-membered ring of germacranes.The acid-induced cyclization of the germacranes synthesized in this way mimics the biosynthesis of eudesmane and guaiane sesquiterpenes and is used to study the role of enzymes in these cyclization reactions.In chapter 1, a general introduction into the biosynthesis and physiological role of terpenes is presented.

Herein, we report the first total synthesis and determination of the stereochemistry of 13-hydroxy-α-eudesmol.

Synthesis of (+)-β-eudesmol - ScienceDirect

During the synthesis of 11, a pronounced example of through- bond interactions (TBI) was observed.Neohedycaryol exists preferably in the elongated chair conformation as was determined spectroscopically and by chemical transformation and this indicates that the role of neohedycaryol as a precursor in the biosynthesis of epi-eudesmanes, as proposed in the literature, is unlikely.

The biosynthesis of germacrane sesquiterpenes and their subsequent conversion into eudesmane and guaiane sesquiterpenes is further worked out.

These findings indicate that the occurrence of neohedycaryol as a precursor in the biosynthesis of epi-eudesmanes as proposed in the literature is unlikely.

T1 - Total Synthesis of Neohedycaryol. Its Possible Role in the Biosynthesis of Eudesmane Sesquiterpenes


Total synthesis and stereochemistry of 13-hydroxy-α-eudesmol

A facile synthetic route to two new carbon skeleton sesquiterpenes 4,5-dioxo-seco-γ-eudesmol and 5β,11-dihydroxyiphionan-4-one from (+)-dihydrocarvone has been described. The configuration of the 5β,11-dihydroxyiphionan-4-one was confirmed by stereospecific synthesis.

Total Synthesis and Stereochemistry of 13-Hydroxy-α-eudesmol

Practical and stereoselective total synthesis of (-)-α-eudesmol 1, a P/Q-type calcium channel blocker, has been achieved with the key step being a cyclopropane ring opening accompanying introduction of a hydroxyl group. (+)-Carissone is used as a key intermediate.

Synthesis of 4,5-seco-eudesman-type sesquiterpenes: …

This also means that 12 is not chiral and occupies a meso form.In chapter 6, enolate-assisted fragmentation reactions are developed for the synthesis of germacranes.