2‐(Diphenylphosphinoyl)acetyl Group Enabled Divergent Synthesis of 2′‐ O ‐Acetyl Phenylethanoid Glycosides

ABSTRACT Phenylethanoid glycosides (PGs), featuring a phenylethanoid glucoside core, exhibit diverse biological activities, notably neuroprotective effects. However, PGs bearing the susceptible 2′‐ O ‐acetyl group remain scarcely explored owing to their limited natural occurrence and the difficulty of preserving esters during synthesis. Herein, we describe the synthesis of such PGs, keeping the 2′‐ O ‐acetyl group intact via a remote DPPA‐directed glycosylation strategy. The 2‐(diphenylphosphinoyl)acetyl (DPPA) group ensures high stereocontrol through hydrogen‐bonding in glycosylation, and can be selectively removed under mild Mg(OMe) 2 ‐promoted conditions. This approach enables streamlined access to both acetylated and non‐acetylated PGs, including cistanosides E, G, and H, as well as the proposed structure of lophanthoside A. The developed method provides a general platform for constructing PGs bearing acyl groups and supports further investigation of their bioactive mechanisms.