Although not as exciting as it used to be, Fujita’s crystalline sponge technology has reached another milestone. This time the group could determine the absolute configuration of a natural product elatenyne. Burton lab from Oxford attempted (and not once) the total synthesis of the product with a sole purpose to assign its structure and absolute configuration. But to achieve that, one needs a good reference analytical data of the natural sample in the first place. And this was the bottleneck for the featured compound. Owing to its almost symmetrical structure, the molecule doesn’t rotate the polarized light by a lot (the latest [α]D values from Burton and Kim labs were −1.6° and +0.80° for two enantiomers). But reported data for ‘natural’ elatenyne varied from +19° to −10°. Which would make ambiguous even a qualitative judgement about the synthesized compound.
And as you can imagine, the molecule doesn’t easily crystallize in a conventional way. So it was an ideal case to try soaking a crystalline sponge in a solution of the compound. Remarkably, Fujita’s group needed only 5 μg of the freshly isolated compound for the analysis. As the result, they confirmed that Burton’s structure was correct.
No comments on bioactivity though.