Artemisinin is an important drug to fight malaria. It is produced either by extraction or via a semisynthetic route involving enzyme engineering. A key intermediate to produce artemisinin by the enzymatic route is dihydroartemisinic aldehyde (DHAAl). However, control of the absolute configuration of the stereocenter α to the aldehyde is highly challenging. Herein we report a protocol that allows the diastereomeric enrichment of a mixture of (11R)/(11S)-DHAAl to the desired (11R)-DHAAl by utilizing a crystallization-induced diastereomer transformation induced by the Betti base. In addition, the Betti base can be quantitatively recovered and reused after the reaction.

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The microfluidic production of highly stable foams using newly synthetized polyfluorinated surfactants is reported herein.