From d- to l‑Monosaccharide Derivatives via Photodecarboxylation–Alkylation

Photodecarboxylation–alkylation of conformationally locked monosaccharides leads to inversion of stereochemistry at C5. This allows the synthesis of l-sugars from their readily available d-counterparts. Via this strategy, methyl l-guloside was synthesized from methyl d-mannoside in 21% yield over six steps.