Blue light photoredox decarboxylation and tin-free Barton-McCombie reactions in the stereoselective synthesis of (+)-muscarine

Starting from a 1,2-O-isopropylidene-α-d-xylofuranose derivative, a non-toxic free-radical approach for the synthesis of (+)-muscarine is reported. To this end, a stereoselective allylation reaction at the anomeric position of a respective xylofuranose derivative was employed as a new synthetic strategy for the installation of the methyl group at the C-5 position of (+)-muscarine. Accordingly, the allyl group was transformed into the methyl group in three sequential steps highlighting a blue-light photoredox decarboxylation reaction. Additionally, a tin-free Barton-McCombie deoxygenation reaction of the respective C-methyl glycoside allowed the completion of this free-radical approach to (+)-muscarine.