Branched tetrahydrofuran α,α-disubstituted-δ-sugar amino acid scaffolds from branched sugar lactones: a new family of foldamers?

Efficient S_N2 ring closure of open chain trihydroxytriflates—in which the leaving group is on a primary carbon adjacent to a quaternary centre—provides access to tetrahydrofurans with branched carbon chains from branched carbohydrate lactones; the first examples of a new class of branched chain tetrahydrofuran α,α-disubstituted-δ-sugar amino acid scaffolds are described.