Erysodienone is a key precursor in the

biosynthesis Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...

of many ''

Erythrina ''Erythrina'' is a genus of plants in the pea family, Fabaceae. It contains about 130 species, which are distributed in tropical and subtropical regions worldwide. They are trees, with the larger species growing up to in height. The generic na ...

''-produced

alkaloids Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar st ...

. Early work was done by Derek Barton and co-workers to illustrate the biosynthetic pathways towards erythrina alkaloids. It was demonstrated that erysodienone could be synthesized from simple starting materials by a similar approach as its biosynthetic pathway, which led to the development of the biomimetic synthesis of erysodienone.

Synthesis

The biosynthesis of erysodienone involves a key step of

oxidative Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...

phenol coupling. Starting with S-norprotosinomenine precursor A, cyclization via oxidative phenol coupling forms intermediate B, which in turn can be rearranged to form intermediate C. Hydrogenation of C forms the diphenoquinone intermediate E. An intramolecular Michael addition reaction converts E to the final product, erysodienone. : Structure of erysodienone and its proposed biosynthetic pathway

Structure of erysodienone and its proposed biosynthetic pathway

A biomimetic synthesis route for erysodienone was developed based on a similar oxidative phenol coupling mechanism. Barton and co-workers found that treating bisphenolethylamine precursor F with oxidants such as

K3Fe(CN)6 Potassium ferricyanide is the chemical compound with the formula K3 e(CN)6 This bright red salt contains the octahedrally coordinated 3−">e(CN)6sup>3− ion. It is soluble in water and its solution shows some green-yellow fluorescence. I ...

initiated oxidative phenol coupling to form the 9-membered ring structure in intermediate D that itself undergo a Michael addition to give erysodienone. : Biomimetic synthesis of erysodienone

Synthesis

References

Further reading