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

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.