Application of the Barbier‐type indium‐mediated allylation method to suitable substrates offers access to carbohydrates bearing a terminal olefin moiety. The C–C bond forming reaction generates a defined stereochemistry of the new chiral center and tolerates a wide variety of starting aldehydes thus allowing modifications in the carbohydrate backbone. Further transformations of the alkene moiety via an environmentally benign and subtle controlled protocol using potassium permanganate gives rise to the structural motif of 3‐deoxy‐2‐uloses in good yields. The final part of the reaction sequence focuses on the deprotection of the acetyl groups essential for the success of the oxidation step. The acidic and labile 3‐deoxy position of the target molecule is prone to elimination applying standard deacetylation conditions and therefore demands derivatisation of the molecule. The introduction of a thioketal moiety using microwave conditions shows promising results and subsequent standard transformations are applicable leading to the desired products.
A two-step reaction sequence starting with the indium-mediated allenylation of aldehydes with 4-bromo-2-butyn-1-ols and subsequent ozonolysis of the resulting allenylic product was developed to generate a variety of dihydroxyacetone derivatives. The regioselectivity of the indium-promoted C-C bond-forming reaction can be manipulated through hydroxy protecting groups on 4-bromo-2-butyn-1-ol, yielding either
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.