Total Synthesis Blog

Today, some nice-looking target – isolated from germinating sunflowers (Helianthus annus L.) – (+)-Sundiversifolide:

Nice structure and nice name (however, I prefer snow ). (+)-Sundiversifolide exhibits some interesting biological properties. For example it can inhibit root growth of some plants. Also it can inhibit (in small concentrations – about 100 μM) germination of some fungi species and therefore it can be used as natural herbicide.

Below I’ve shown my retrosynthetic approach to (+)-Sundiversifolide:

(Click on image to enlarge it)

The key steps involve Diels-Alder cyclization, ring expansion (with use diazo compound) and TPAP-promoted cyclization (see also Total Synthesis of Bruguierol C for other application of that key reaction). I’m waiting for your opinions.

The real retrosynthesis of (+)-Sundiversifolide is shown below:
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Today, some interesting tricyclic target, Alboatrin:

Alboatrin has characteristic cis tetrahydofurane-benzenopyrane system. Also, there is ketal moiety present in this molecule what (in my opinion) can be taken advantage in planning of synthesis of Alboatrin (well, in my retrosynthesis I’ve taken advantage of this fact ).

Let’s say something about properties of our target. Well, Alboatrin was isolated from Verticillium alboatrum (some fungi specie, I guess). It exhibits phytotoxic activity, for example – it inhibits the root growth.

Retrosynthesis is shown below:

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