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Significant amounts  of research the past years has greatly enhanced the knowledge surrounding Alzheimer´s disease and resulted in approval of the monoclonal antibody aducanumab (Aduhelm) 2021 in USA. Due to conflicting results surrounding the drug´s efficacy, Aducanumab´s approval was controversial. Regardless, drugs which slow, impede or reverse the disease progression is needed. One previous approach for development of novel Alzheimer´s disease treatment is based on Angiotensin IV (Ang IV). This peptide´s signaling pathways is associated with improved cognition, memory functions, is neuroprotective and favors long-term potentiation. Ang IV-analogues have been developed as Leads and/or Hits, targeting the AT4-receptor (IRAP). One class of analogues are macrocyclic IRAP-inhibitors, several which have shown higher IRAP-affinity and enzymatic stability compared to Ang IV, for example cyclized[(S)-homocysteine-(S)-β3homotyrosine-(R)-homocysteine]-2-(aminomethyl)phenylacetic acid (HA-08), see figure 1. A non-investigated structure activity relationship of peptidomimetics with a similar structure to HA08 is α-fluorination of β3homotyrosine (β3hTyr). To synthesize this α-difluorinated HA08, a peptide synthesis approach using α-difluoro β3hTyr as a building block can be used. Previous synthesis of α-difluoro β3 amino acids depend on air sensitive Reformatsky reagents, these reagents require tedious and unreliable zinc activation to acquire. The aim of this study was to investigate a photochemical approach to synthesize α-difluoro β3 amino acids via sulfinylimines and ethyl bromodifluoroacetate. The evaluated photochemical synthesis of α-difluoro β3 amino acids were non-successful. These results were attributed to insufficient electrophilicity of the sulfinylimine-carbon and competing photochemical side reactions involving the sulfinylimine, forming the corresponding 4-methylphenyl thiosulfonate and disulfide. Another important finding werethat the undesired side reaction is counteracted by performing the reaction in anhydrous THF under basic conditions. While including trifluoroacetic acid in the THF-reaction mixture as an additive further facilitated the formation of the corresponding 4-methylphenyl thiosulfonate and disulfide.