Researchers at the University of Bristol have developed a method for “flipping” molecules by changing their spatial structure. This could radically simplify the synthesis of compounds used in medicines, including breast cancer drugs. The findings of the study were published in the journal Nature.

The key to the technology is the ability to change the chirality of molecules; converting right-rotating forms into left-rotating ones and vice versa. According to the head of the research, Professor Varinder Aggarwal, this enables to create safe analogues of medical drugs such as Tamoxifen, which is used to treat breast cancer.

According to the researchers, tetravalent alkenes—complex molecules in which four different groups are attached to a carbon double bond—are of particular interest. They are important in pharmaceuticals, but their synthesis has traditionally been a difficult task.

Initially, researchers tried using organoboron ethers, but the compounds were unstable. Progress was made when they were replaced by borohydrides, which enabled the molecules to “rotate” properly.

“This new boron system enabled the installation of different groups on the alkene in a controlled manner from very simple building blocks, like Lego,” Aggarwal explains.

Computer simulations conducted at the University of Colorado confirmed that the geometry of an alkene can indeed be changed instantaneously by simply adding a reagent.

“This was surprising  and hadn’t been seen before,” admits study co-author Robert Paton.

The method has already been tested on the molecules Tamoxifen and γ-bisabolene, a component of essential oils. Now researchers hope to apply it to other domains—from the development of new medical drugs to the creation of materials with predefined properties.